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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network169.254.128.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
169.254.128.0
Broadcast address
169.254.143.255
First usable
169.254.128.1
Last usable
169.254.143.254
Usable hosts
4,094 (4,096 less the network and broadcast addresses)
Subnet mask
255.255.240.0
Wildcard mask
0.0.15.255 (Cisco ACLs, OSPF)
Prefix length
/20
Type
Link-local (APIPA) 169.254.0.0/16
Self-assigned when no DHCP server answers
Old class
B (default /16)
As numbers
Hex A9FE8000 · Integer 2852028416 to 2852032511
Reverse DNS zones
128.254.169.in-addr.arpa
129.254.169.in-addr.arpa
130.254.169.in-addr.arpa
131.254.169.in-addr.arpa
132.254.169.in-addr.arpa
133.254.169.in-addr.arpa
134.254.169.in-addr.arpa
135.254.169.in-addr.arpa
136.254.169.in-addr.arpa
137.254.169.in-addr.arpa
138.254.169.in-addr.arpa
139.254.169.in-addr.arpa
140.254.169.in-addr.arpa
141.254.169.in-addr.arpa
142.254.169.in-addr.arpa
143.254.169.in-addr.arpa
/20 is not on a 8-bit boundary, so it takes 16 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10101001.11111110.10000000.00000000169.254.128.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network10101001.11111110.10000000.00000000169.254.128.0
Broadcast10101001.11111110.10001111.11111111169.254.143.255
Split into smaller subnets/28
/21 (2)/22 (4)/23 (8)/24 (16)/25 (32)/26 (64)/27 (128)/28 (256)/29 (512)/30 (1,024)/31 (2,048)/32 (4,096)

169.254.128.0/20 makes 256 subnets of /28.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1169.254.128.0/28169.254.128.1 to 169.254.128.14169.254.128.1514
2169.254.128.16/28169.254.128.17 to 169.254.128.30169.254.128.3114
3169.254.128.32/28169.254.128.33 to 169.254.128.46169.254.128.4714
4169.254.128.48/28169.254.128.49 to 169.254.128.62169.254.128.6314
5169.254.128.64/28169.254.128.65 to 169.254.128.78169.254.128.7914
6169.254.128.80/28169.254.128.81 to 169.254.128.94169.254.128.9514
7169.254.128.96/28169.254.128.97 to 169.254.128.110169.254.128.11114
8169.254.128.112/28169.254.128.113 to 169.254.128.126169.254.128.12714
9169.254.128.128/28169.254.128.129 to 169.254.128.142169.254.128.14314
10169.254.128.144/28169.254.128.145 to 169.254.128.158169.254.128.15914
11169.254.128.160/28169.254.128.161 to 169.254.128.174169.254.128.17514
12169.254.128.176/28169.254.128.177 to 169.254.128.190169.254.128.19114
13169.254.128.192/28169.254.128.193 to 169.254.128.206169.254.128.20714
14169.254.128.208/28169.254.128.209 to 169.254.128.222169.254.128.22314
15169.254.128.224/28169.254.128.225 to 169.254.128.238169.254.128.23914
16169.254.128.240/28169.254.128.241 to 169.254.128.254169.254.128.25514
17169.254.129.0/28169.254.129.1 to 169.254.129.14169.254.129.1514
18169.254.129.16/28169.254.129.17 to 169.254.129.30169.254.129.3114
19169.254.129.32/28169.254.129.33 to 169.254.129.46169.254.129.4714
20169.254.129.48/28169.254.129.49 to 169.254.129.62169.254.129.6314
21169.254.129.64/28169.254.129.65 to 169.254.129.78169.254.129.7914
22169.254.129.80/28169.254.129.81 to 169.254.129.94169.254.129.9514
23169.254.129.96/28169.254.129.97 to 169.254.129.110169.254.129.11114
24169.254.129.112/28169.254.129.113 to 169.254.129.126169.254.129.12714
25169.254.129.128/28169.254.129.129 to 169.254.129.142169.254.129.14314
26169.254.129.144/28169.254.129.145 to 169.254.129.158169.254.129.15914
27169.254.129.160/28169.254.129.161 to 169.254.129.174169.254.129.17514
28169.254.129.176/28169.254.129.177 to 169.254.129.190169.254.129.19114
29169.254.129.192/28169.254.129.193 to 169.254.129.206169.254.129.20714
30169.254.129.208/28169.254.129.209 to 169.254.129.222169.254.129.22314
31169.254.129.224/28169.254.129.225 to 169.254.129.238169.254.129.23914
32169.254.129.240/28169.254.129.241 to 169.254.129.254169.254.129.25514
33169.254.130.0/28169.254.130.1 to 169.254.130.14169.254.130.1514
34169.254.130.16/28169.254.130.17 to 169.254.130.30169.254.130.3114
35169.254.130.32/28169.254.130.33 to 169.254.130.46169.254.130.4714
36169.254.130.48/28169.254.130.49 to 169.254.130.62169.254.130.6314
37169.254.130.64/28169.254.130.65 to 169.254.130.78169.254.130.7914
38169.254.130.80/28169.254.130.81 to 169.254.130.94169.254.130.9514
39169.254.130.96/28169.254.130.97 to 169.254.130.110169.254.130.11114
40169.254.130.112/28169.254.130.113 to 169.254.130.126169.254.130.12714
41169.254.130.128/28169.254.130.129 to 169.254.130.142169.254.130.14314
42169.254.130.144/28169.254.130.145 to 169.254.130.158169.254.130.15914
43169.254.130.160/28169.254.130.161 to 169.254.130.174169.254.130.17514
44169.254.130.176/28169.254.130.177 to 169.254.130.190169.254.130.19114
45169.254.130.192/28169.254.130.193 to 169.254.130.206169.254.130.20714
46169.254.130.208/28169.254.130.209 to 169.254.130.222169.254.130.22314
47169.254.130.224/28169.254.130.225 to 169.254.130.238169.254.130.23914
48169.254.130.240/28169.254.130.241 to 169.254.130.254169.254.130.25514
49169.254.131.0/28169.254.131.1 to 169.254.131.14169.254.131.1514
50169.254.131.16/28169.254.131.17 to 169.254.131.30169.254.131.3114
51169.254.131.32/28169.254.131.33 to 169.254.131.46169.254.131.4714
52169.254.131.48/28169.254.131.49 to 169.254.131.62169.254.131.6314
53169.254.131.64/28169.254.131.65 to 169.254.131.78169.254.131.7914
54169.254.131.80/28169.254.131.81 to 169.254.131.94169.254.131.9514
55169.254.131.96/28169.254.131.97 to 169.254.131.110169.254.131.11114
56169.254.131.112/28169.254.131.113 to 169.254.131.126169.254.131.12714
57169.254.131.128/28169.254.131.129 to 169.254.131.142169.254.131.14314
58169.254.131.144/28169.254.131.145 to 169.254.131.158169.254.131.15914
59169.254.131.160/28169.254.131.161 to 169.254.131.174169.254.131.17514
60169.254.131.176/28169.254.131.177 to 169.254.131.190169.254.131.19114
61169.254.131.192/28169.254.131.193 to 169.254.131.206169.254.131.20714
62169.254.131.208/28169.254.131.209 to 169.254.131.222169.254.131.22314
63169.254.131.224/28169.254.131.225 to 169.254.131.238169.254.131.23914
64169.254.131.240/28169.254.131.241 to 169.254.131.254169.254.131.25514
65169.254.132.0/28169.254.132.1 to 169.254.132.14169.254.132.1514
66169.254.132.16/28169.254.132.17 to 169.254.132.30169.254.132.3114
67169.254.132.32/28169.254.132.33 to 169.254.132.46169.254.132.4714
68169.254.132.48/28169.254.132.49 to 169.254.132.62169.254.132.6314
69169.254.132.64/28169.254.132.65 to 169.254.132.78169.254.132.7914
70169.254.132.80/28169.254.132.81 to 169.254.132.94169.254.132.9514
71169.254.132.96/28169.254.132.97 to 169.254.132.110169.254.132.11114
72169.254.132.112/28169.254.132.113 to 169.254.132.126169.254.132.12714
73169.254.132.128/28169.254.132.129 to 169.254.132.142169.254.132.14314
74169.254.132.144/28169.254.132.145 to 169.254.132.158169.254.132.15914
75169.254.132.160/28169.254.132.161 to 169.254.132.174169.254.132.17514
76169.254.132.176/28169.254.132.177 to 169.254.132.190169.254.132.19114
77169.254.132.192/28169.254.132.193 to 169.254.132.206169.254.132.20714
78169.254.132.208/28169.254.132.209 to 169.254.132.222169.254.132.22314
79169.254.132.224/28169.254.132.225 to 169.254.132.238169.254.132.23914
80169.254.132.240/28169.254.132.241 to 169.254.132.254169.254.132.25514
81169.254.133.0/28169.254.133.1 to 169.254.133.14169.254.133.1514
82169.254.133.16/28169.254.133.17 to 169.254.133.30169.254.133.3114
83169.254.133.32/28169.254.133.33 to 169.254.133.46169.254.133.4714
84169.254.133.48/28169.254.133.49 to 169.254.133.62169.254.133.6314
85169.254.133.64/28169.254.133.65 to 169.254.133.78169.254.133.7914
86169.254.133.80/28169.254.133.81 to 169.254.133.94169.254.133.9514
87169.254.133.96/28169.254.133.97 to 169.254.133.110169.254.133.11114
88169.254.133.112/28169.254.133.113 to 169.254.133.126169.254.133.12714
89169.254.133.128/28169.254.133.129 to 169.254.133.142169.254.133.14314
90169.254.133.144/28169.254.133.145 to 169.254.133.158169.254.133.15914
91169.254.133.160/28169.254.133.161 to 169.254.133.174169.254.133.17514
92169.254.133.176/28169.254.133.177 to 169.254.133.190169.254.133.19114
93169.254.133.192/28169.254.133.193 to 169.254.133.206169.254.133.20714
94169.254.133.208/28169.254.133.209 to 169.254.133.222169.254.133.22314
95169.254.133.224/28169.254.133.225 to 169.254.133.238169.254.133.23914
96169.254.133.240/28169.254.133.241 to 169.254.133.254169.254.133.25514
97169.254.134.0/28169.254.134.1 to 169.254.134.14169.254.134.1514
98169.254.134.16/28169.254.134.17 to 169.254.134.30169.254.134.3114
99169.254.134.32/28169.254.134.33 to 169.254.134.46169.254.134.4714
100169.254.134.48/28169.254.134.49 to 169.254.134.62169.254.134.6314
101169.254.134.64/28169.254.134.65 to 169.254.134.78169.254.134.7914
102169.254.134.80/28169.254.134.81 to 169.254.134.94169.254.134.9514
103169.254.134.96/28169.254.134.97 to 169.254.134.110169.254.134.11114
104169.254.134.112/28169.254.134.113 to 169.254.134.126169.254.134.12714
105169.254.134.128/28169.254.134.129 to 169.254.134.142169.254.134.14314
106169.254.134.144/28169.254.134.145 to 169.254.134.158169.254.134.15914
107169.254.134.160/28169.254.134.161 to 169.254.134.174169.254.134.17514
108169.254.134.176/28169.254.134.177 to 169.254.134.190169.254.134.19114
109169.254.134.192/28169.254.134.193 to 169.254.134.206169.254.134.20714
110169.254.134.208/28169.254.134.209 to 169.254.134.222169.254.134.22314
111169.254.134.224/28169.254.134.225 to 169.254.134.238169.254.134.23914
112169.254.134.240/28169.254.134.241 to 169.254.134.254169.254.134.25514
113169.254.135.0/28169.254.135.1 to 169.254.135.14169.254.135.1514
114169.254.135.16/28169.254.135.17 to 169.254.135.30169.254.135.3114
115169.254.135.32/28169.254.135.33 to 169.254.135.46169.254.135.4714
116169.254.135.48/28169.254.135.49 to 169.254.135.62169.254.135.6314
117169.254.135.64/28169.254.135.65 to 169.254.135.78169.254.135.7914
118169.254.135.80/28169.254.135.81 to 169.254.135.94169.254.135.9514
119169.254.135.96/28169.254.135.97 to 169.254.135.110169.254.135.11114
120169.254.135.112/28169.254.135.113 to 169.254.135.126169.254.135.12714
121169.254.135.128/28169.254.135.129 to 169.254.135.142169.254.135.14314
122169.254.135.144/28169.254.135.145 to 169.254.135.158169.254.135.15914
123169.254.135.160/28169.254.135.161 to 169.254.135.174169.254.135.17514
124169.254.135.176/28169.254.135.177 to 169.254.135.190169.254.135.19114
125169.254.135.192/28169.254.135.193 to 169.254.135.206169.254.135.20714
126169.254.135.208/28169.254.135.209 to 169.254.135.222169.254.135.22314
127169.254.135.224/28169.254.135.225 to 169.254.135.238169.254.135.23914
128169.254.135.240/28169.254.135.241 to 169.254.135.254169.254.135.25514
129169.254.136.0/28169.254.136.1 to 169.254.136.14169.254.136.1514
130169.254.136.16/28169.254.136.17 to 169.254.136.30169.254.136.3114
131169.254.136.32/28169.254.136.33 to 169.254.136.46169.254.136.4714
132169.254.136.48/28169.254.136.49 to 169.254.136.62169.254.136.6314
133169.254.136.64/28169.254.136.65 to 169.254.136.78169.254.136.7914
134169.254.136.80/28169.254.136.81 to 169.254.136.94169.254.136.9514
135169.254.136.96/28169.254.136.97 to 169.254.136.110169.254.136.11114
136169.254.136.112/28169.254.136.113 to 169.254.136.126169.254.136.12714
137169.254.136.128/28169.254.136.129 to 169.254.136.142169.254.136.14314
138169.254.136.144/28169.254.136.145 to 169.254.136.158169.254.136.15914
139169.254.136.160/28169.254.136.161 to 169.254.136.174169.254.136.17514
140169.254.136.176/28169.254.136.177 to 169.254.136.190169.254.136.19114
141169.254.136.192/28169.254.136.193 to 169.254.136.206169.254.136.20714
142169.254.136.208/28169.254.136.209 to 169.254.136.222169.254.136.22314
143169.254.136.224/28169.254.136.225 to 169.254.136.238169.254.136.23914
144169.254.136.240/28169.254.136.241 to 169.254.136.254169.254.136.25514
145169.254.137.0/28169.254.137.1 to 169.254.137.14169.254.137.1514
146169.254.137.16/28169.254.137.17 to 169.254.137.30169.254.137.3114
147169.254.137.32/28169.254.137.33 to 169.254.137.46169.254.137.4714
148169.254.137.48/28169.254.137.49 to 169.254.137.62169.254.137.6314
149169.254.137.64/28169.254.137.65 to 169.254.137.78169.254.137.7914
150169.254.137.80/28169.254.137.81 to 169.254.137.94169.254.137.9514
151169.254.137.96/28169.254.137.97 to 169.254.137.110169.254.137.11114
152169.254.137.112/28169.254.137.113 to 169.254.137.126169.254.137.12714
153169.254.137.128/28169.254.137.129 to 169.254.137.142169.254.137.14314
154169.254.137.144/28169.254.137.145 to 169.254.137.158169.254.137.15914
155169.254.137.160/28169.254.137.161 to 169.254.137.174169.254.137.17514
156169.254.137.176/28169.254.137.177 to 169.254.137.190169.254.137.19114
157169.254.137.192/28169.254.137.193 to 169.254.137.206169.254.137.20714
158169.254.137.208/28169.254.137.209 to 169.254.137.222169.254.137.22314
159169.254.137.224/28169.254.137.225 to 169.254.137.238169.254.137.23914
160169.254.137.240/28169.254.137.241 to 169.254.137.254169.254.137.25514
161169.254.138.0/28169.254.138.1 to 169.254.138.14169.254.138.1514
162169.254.138.16/28169.254.138.17 to 169.254.138.30169.254.138.3114
163169.254.138.32/28169.254.138.33 to 169.254.138.46169.254.138.4714
164169.254.138.48/28169.254.138.49 to 169.254.138.62169.254.138.6314
165169.254.138.64/28169.254.138.65 to 169.254.138.78169.254.138.7914
166169.254.138.80/28169.254.138.81 to 169.254.138.94169.254.138.9514
167169.254.138.96/28169.254.138.97 to 169.254.138.110169.254.138.11114
168169.254.138.112/28169.254.138.113 to 169.254.138.126169.254.138.12714
169169.254.138.128/28169.254.138.129 to 169.254.138.142169.254.138.14314
170169.254.138.144/28169.254.138.145 to 169.254.138.158169.254.138.15914
171169.254.138.160/28169.254.138.161 to 169.254.138.174169.254.138.17514
172169.254.138.176/28169.254.138.177 to 169.254.138.190169.254.138.19114
173169.254.138.192/28169.254.138.193 to 169.254.138.206169.254.138.20714
174169.254.138.208/28169.254.138.209 to 169.254.138.222169.254.138.22314
175169.254.138.224/28169.254.138.225 to 169.254.138.238169.254.138.23914
176169.254.138.240/28169.254.138.241 to 169.254.138.254169.254.138.25514
177169.254.139.0/28169.254.139.1 to 169.254.139.14169.254.139.1514
178169.254.139.16/28169.254.139.17 to 169.254.139.30169.254.139.3114
179169.254.139.32/28169.254.139.33 to 169.254.139.46169.254.139.4714
180169.254.139.48/28169.254.139.49 to 169.254.139.62169.254.139.6314
181169.254.139.64/28169.254.139.65 to 169.254.139.78169.254.139.7914
182169.254.139.80/28169.254.139.81 to 169.254.139.94169.254.139.9514
183169.254.139.96/28169.254.139.97 to 169.254.139.110169.254.139.11114
184169.254.139.112/28169.254.139.113 to 169.254.139.126169.254.139.12714
185169.254.139.128/28169.254.139.129 to 169.254.139.142169.254.139.14314
186169.254.139.144/28169.254.139.145 to 169.254.139.158169.254.139.15914
187169.254.139.160/28169.254.139.161 to 169.254.139.174169.254.139.17514
188169.254.139.176/28169.254.139.177 to 169.254.139.190169.254.139.19114
189169.254.139.192/28169.254.139.193 to 169.254.139.206169.254.139.20714
190169.254.139.208/28169.254.139.209 to 169.254.139.222169.254.139.22314
191169.254.139.224/28169.254.139.225 to 169.254.139.238169.254.139.23914
192169.254.139.240/28169.254.139.241 to 169.254.139.254169.254.139.25514
193169.254.140.0/28169.254.140.1 to 169.254.140.14169.254.140.1514
194169.254.140.16/28169.254.140.17 to 169.254.140.30169.254.140.3114
195169.254.140.32/28169.254.140.33 to 169.254.140.46169.254.140.4714
196169.254.140.48/28169.254.140.49 to 169.254.140.62169.254.140.6314
197169.254.140.64/28169.254.140.65 to 169.254.140.78169.254.140.7914
198169.254.140.80/28169.254.140.81 to 169.254.140.94169.254.140.9514
199169.254.140.96/28169.254.140.97 to 169.254.140.110169.254.140.11114
200169.254.140.112/28169.254.140.113 to 169.254.140.126169.254.140.12714
201169.254.140.128/28169.254.140.129 to 169.254.140.142169.254.140.14314
202169.254.140.144/28169.254.140.145 to 169.254.140.158169.254.140.15914
203169.254.140.160/28169.254.140.161 to 169.254.140.174169.254.140.17514
204169.254.140.176/28169.254.140.177 to 169.254.140.190169.254.140.19114
205169.254.140.192/28169.254.140.193 to 169.254.140.206169.254.140.20714
206169.254.140.208/28169.254.140.209 to 169.254.140.222169.254.140.22314
207169.254.140.224/28169.254.140.225 to 169.254.140.238169.254.140.23914
208169.254.140.240/28169.254.140.241 to 169.254.140.254169.254.140.25514
209169.254.141.0/28169.254.141.1 to 169.254.141.14169.254.141.1514
210169.254.141.16/28169.254.141.17 to 169.254.141.30169.254.141.3114
211169.254.141.32/28169.254.141.33 to 169.254.141.46169.254.141.4714
212169.254.141.48/28169.254.141.49 to 169.254.141.62169.254.141.6314
213169.254.141.64/28169.254.141.65 to 169.254.141.78169.254.141.7914
214169.254.141.80/28169.254.141.81 to 169.254.141.94169.254.141.9514
215169.254.141.96/28169.254.141.97 to 169.254.141.110169.254.141.11114
216169.254.141.112/28169.254.141.113 to 169.254.141.126169.254.141.12714
217169.254.141.128/28169.254.141.129 to 169.254.141.142169.254.141.14314
218169.254.141.144/28169.254.141.145 to 169.254.141.158169.254.141.15914
219169.254.141.160/28169.254.141.161 to 169.254.141.174169.254.141.17514
220169.254.141.176/28169.254.141.177 to 169.254.141.190169.254.141.19114
221169.254.141.192/28169.254.141.193 to 169.254.141.206169.254.141.20714
222169.254.141.208/28169.254.141.209 to 169.254.141.222169.254.141.22314
223169.254.141.224/28169.254.141.225 to 169.254.141.238169.254.141.23914
224169.254.141.240/28169.254.141.241 to 169.254.141.254169.254.141.25514
225169.254.142.0/28169.254.142.1 to 169.254.142.14169.254.142.1514
226169.254.142.16/28169.254.142.17 to 169.254.142.30169.254.142.3114
227169.254.142.32/28169.254.142.33 to 169.254.142.46169.254.142.4714
228169.254.142.48/28169.254.142.49 to 169.254.142.62169.254.142.6314
229169.254.142.64/28169.254.142.65 to 169.254.142.78169.254.142.7914
230169.254.142.80/28169.254.142.81 to 169.254.142.94169.254.142.9514
231169.254.142.96/28169.254.142.97 to 169.254.142.110169.254.142.11114
232169.254.142.112/28169.254.142.113 to 169.254.142.126169.254.142.12714
233169.254.142.128/28169.254.142.129 to 169.254.142.142169.254.142.14314
234169.254.142.144/28169.254.142.145 to 169.254.142.158169.254.142.15914
235169.254.142.160/28169.254.142.161 to 169.254.142.174169.254.142.17514
236169.254.142.176/28169.254.142.177 to 169.254.142.190169.254.142.19114
237169.254.142.192/28169.254.142.193 to 169.254.142.206169.254.142.20714
238169.254.142.208/28169.254.142.209 to 169.254.142.222169.254.142.22314
239169.254.142.224/28169.254.142.225 to 169.254.142.238169.254.142.23914
240169.254.142.240/28169.254.142.241 to 169.254.142.254169.254.142.25514
241169.254.143.0/28169.254.143.1 to 169.254.143.14169.254.143.1514
242169.254.143.16/28169.254.143.17 to 169.254.143.30169.254.143.3114
243169.254.143.32/28169.254.143.33 to 169.254.143.46169.254.143.4714
244169.254.143.48/28169.254.143.49 to 169.254.143.62169.254.143.6314
245169.254.143.64/28169.254.143.65 to 169.254.143.78169.254.143.7914
246169.254.143.80/28169.254.143.81 to 169.254.143.94169.254.143.9514
247169.254.143.96/28169.254.143.97 to 169.254.143.110169.254.143.11114
248169.254.143.112/28169.254.143.113 to 169.254.143.126169.254.143.12714
249169.254.143.128/28169.254.143.129 to 169.254.143.142169.254.143.14314
250169.254.143.144/28169.254.143.145 to 169.254.143.158169.254.143.15914
251169.254.143.160/28169.254.143.161 to 169.254.143.174169.254.143.17514
252169.254.143.176/28169.254.143.177 to 169.254.143.190169.254.143.19114
253169.254.143.192/28169.254.143.193 to 169.254.143.206169.254.143.20714
254169.254.143.208/28169.254.143.209 to 169.254.143.222169.254.143.22314
255169.254.143.224/28169.254.143.225 to 169.254.143.238169.254.143.23914
256169.254.143.240/28169.254.143.241 to 169.254.143.254169.254.143.25514

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.