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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.

Network226.167.0.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
226.167.0.0
Broadcast address
226.167.15.255
First usable
226.167.0.1
Last usable
226.167.15.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E2A70000 · Integer 3802595328 to 3802599423
Reverse DNS zones
0.167.226.in-addr.arpa
1.167.226.in-addr.arpa
2.167.226.in-addr.arpa
3.167.226.in-addr.arpa
4.167.226.in-addr.arpa
5.167.226.in-addr.arpa
6.167.226.in-addr.arpa
7.167.226.in-addr.arpa
8.167.226.in-addr.arpa
9.167.226.in-addr.arpa
10.167.226.in-addr.arpa
11.167.226.in-addr.arpa
12.167.226.in-addr.arpa
13.167.226.in-addr.arpa
14.167.226.in-addr.arpa
15.167.226.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
Address11100010.10100111.00000000.00000000226.167.0.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network11100010.10100111.00000000.00000000226.167.0.0
Broadcast11100010.10100111.00001111.11111111226.167.15.255
Split into smaller subnets/29
/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)

226.167.0.0/20 makes 512 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1226.167.0.0/29226.167.0.1 to 226.167.0.6226.167.0.76
2226.167.0.8/29226.167.0.9 to 226.167.0.14226.167.0.156
3226.167.0.16/29226.167.0.17 to 226.167.0.22226.167.0.236
4226.167.0.24/29226.167.0.25 to 226.167.0.30226.167.0.316
5226.167.0.32/29226.167.0.33 to 226.167.0.38226.167.0.396
6226.167.0.40/29226.167.0.41 to 226.167.0.46226.167.0.476
7226.167.0.48/29226.167.0.49 to 226.167.0.54226.167.0.556
8226.167.0.56/29226.167.0.57 to 226.167.0.62226.167.0.636
9226.167.0.64/29226.167.0.65 to 226.167.0.70226.167.0.716
10226.167.0.72/29226.167.0.73 to 226.167.0.78226.167.0.796
11226.167.0.80/29226.167.0.81 to 226.167.0.86226.167.0.876
12226.167.0.88/29226.167.0.89 to 226.167.0.94226.167.0.956
13226.167.0.96/29226.167.0.97 to 226.167.0.102226.167.0.1036
14226.167.0.104/29226.167.0.105 to 226.167.0.110226.167.0.1116
15226.167.0.112/29226.167.0.113 to 226.167.0.118226.167.0.1196
16226.167.0.120/29226.167.0.121 to 226.167.0.126226.167.0.1276
17226.167.0.128/29226.167.0.129 to 226.167.0.134226.167.0.1356
18226.167.0.136/29226.167.0.137 to 226.167.0.142226.167.0.1436
19226.167.0.144/29226.167.0.145 to 226.167.0.150226.167.0.1516
20226.167.0.152/29226.167.0.153 to 226.167.0.158226.167.0.1596
21226.167.0.160/29226.167.0.161 to 226.167.0.166226.167.0.1676
22226.167.0.168/29226.167.0.169 to 226.167.0.174226.167.0.1756
23226.167.0.176/29226.167.0.177 to 226.167.0.182226.167.0.1836
24226.167.0.184/29226.167.0.185 to 226.167.0.190226.167.0.1916
25226.167.0.192/29226.167.0.193 to 226.167.0.198226.167.0.1996
26226.167.0.200/29226.167.0.201 to 226.167.0.206226.167.0.2076
27226.167.0.208/29226.167.0.209 to 226.167.0.214226.167.0.2156
28226.167.0.216/29226.167.0.217 to 226.167.0.222226.167.0.2236
29226.167.0.224/29226.167.0.225 to 226.167.0.230226.167.0.2316
30226.167.0.232/29226.167.0.233 to 226.167.0.238226.167.0.2396
31226.167.0.240/29226.167.0.241 to 226.167.0.246226.167.0.2476
32226.167.0.248/29226.167.0.249 to 226.167.0.254226.167.0.2556
33226.167.1.0/29226.167.1.1 to 226.167.1.6226.167.1.76
34226.167.1.8/29226.167.1.9 to 226.167.1.14226.167.1.156
35226.167.1.16/29226.167.1.17 to 226.167.1.22226.167.1.236
36226.167.1.24/29226.167.1.25 to 226.167.1.30226.167.1.316
37226.167.1.32/29226.167.1.33 to 226.167.1.38226.167.1.396
38226.167.1.40/29226.167.1.41 to 226.167.1.46226.167.1.476
39226.167.1.48/29226.167.1.49 to 226.167.1.54226.167.1.556
40226.167.1.56/29226.167.1.57 to 226.167.1.62226.167.1.636
41226.167.1.64/29226.167.1.65 to 226.167.1.70226.167.1.716
42226.167.1.72/29226.167.1.73 to 226.167.1.78226.167.1.796
43226.167.1.80/29226.167.1.81 to 226.167.1.86226.167.1.876
44226.167.1.88/29226.167.1.89 to 226.167.1.94226.167.1.956
45226.167.1.96/29226.167.1.97 to 226.167.1.102226.167.1.1036
46226.167.1.104/29226.167.1.105 to 226.167.1.110226.167.1.1116
47226.167.1.112/29226.167.1.113 to 226.167.1.118226.167.1.1196
48226.167.1.120/29226.167.1.121 to 226.167.1.126226.167.1.1276
49226.167.1.128/29226.167.1.129 to 226.167.1.134226.167.1.1356
50226.167.1.136/29226.167.1.137 to 226.167.1.142226.167.1.1436
51226.167.1.144/29226.167.1.145 to 226.167.1.150226.167.1.1516
52226.167.1.152/29226.167.1.153 to 226.167.1.158226.167.1.1596
53226.167.1.160/29226.167.1.161 to 226.167.1.166226.167.1.1676
54226.167.1.168/29226.167.1.169 to 226.167.1.174226.167.1.1756
55226.167.1.176/29226.167.1.177 to 226.167.1.182226.167.1.1836
56226.167.1.184/29226.167.1.185 to 226.167.1.190226.167.1.1916
57226.167.1.192/29226.167.1.193 to 226.167.1.198226.167.1.1996
58226.167.1.200/29226.167.1.201 to 226.167.1.206226.167.1.2076
59226.167.1.208/29226.167.1.209 to 226.167.1.214226.167.1.2156
60226.167.1.216/29226.167.1.217 to 226.167.1.222226.167.1.2236
61226.167.1.224/29226.167.1.225 to 226.167.1.230226.167.1.2316
62226.167.1.232/29226.167.1.233 to 226.167.1.238226.167.1.2396
63226.167.1.240/29226.167.1.241 to 226.167.1.246226.167.1.2476
64226.167.1.248/29226.167.1.249 to 226.167.1.254226.167.1.2556
65226.167.2.0/29226.167.2.1 to 226.167.2.6226.167.2.76
66226.167.2.8/29226.167.2.9 to 226.167.2.14226.167.2.156
67226.167.2.16/29226.167.2.17 to 226.167.2.22226.167.2.236
68226.167.2.24/29226.167.2.25 to 226.167.2.30226.167.2.316
69226.167.2.32/29226.167.2.33 to 226.167.2.38226.167.2.396
70226.167.2.40/29226.167.2.41 to 226.167.2.46226.167.2.476
71226.167.2.48/29226.167.2.49 to 226.167.2.54226.167.2.556
72226.167.2.56/29226.167.2.57 to 226.167.2.62226.167.2.636
73226.167.2.64/29226.167.2.65 to 226.167.2.70226.167.2.716
74226.167.2.72/29226.167.2.73 to 226.167.2.78226.167.2.796
75226.167.2.80/29226.167.2.81 to 226.167.2.86226.167.2.876
76226.167.2.88/29226.167.2.89 to 226.167.2.94226.167.2.956
77226.167.2.96/29226.167.2.97 to 226.167.2.102226.167.2.1036
78226.167.2.104/29226.167.2.105 to 226.167.2.110226.167.2.1116
79226.167.2.112/29226.167.2.113 to 226.167.2.118226.167.2.1196
80226.167.2.120/29226.167.2.121 to 226.167.2.126226.167.2.1276
81226.167.2.128/29226.167.2.129 to 226.167.2.134226.167.2.1356
82226.167.2.136/29226.167.2.137 to 226.167.2.142226.167.2.1436
83226.167.2.144/29226.167.2.145 to 226.167.2.150226.167.2.1516
84226.167.2.152/29226.167.2.153 to 226.167.2.158226.167.2.1596
85226.167.2.160/29226.167.2.161 to 226.167.2.166226.167.2.1676
86226.167.2.168/29226.167.2.169 to 226.167.2.174226.167.2.1756
87226.167.2.176/29226.167.2.177 to 226.167.2.182226.167.2.1836
88226.167.2.184/29226.167.2.185 to 226.167.2.190226.167.2.1916
89226.167.2.192/29226.167.2.193 to 226.167.2.198226.167.2.1996
90226.167.2.200/29226.167.2.201 to 226.167.2.206226.167.2.2076
91226.167.2.208/29226.167.2.209 to 226.167.2.214226.167.2.2156
92226.167.2.216/29226.167.2.217 to 226.167.2.222226.167.2.2236
93226.167.2.224/29226.167.2.225 to 226.167.2.230226.167.2.2316
94226.167.2.232/29226.167.2.233 to 226.167.2.238226.167.2.2396
95226.167.2.240/29226.167.2.241 to 226.167.2.246226.167.2.2476
96226.167.2.248/29226.167.2.249 to 226.167.2.254226.167.2.2556
97226.167.3.0/29226.167.3.1 to 226.167.3.6226.167.3.76
98226.167.3.8/29226.167.3.9 to 226.167.3.14226.167.3.156
99226.167.3.16/29226.167.3.17 to 226.167.3.22226.167.3.236
100226.167.3.24/29226.167.3.25 to 226.167.3.30226.167.3.316
101226.167.3.32/29226.167.3.33 to 226.167.3.38226.167.3.396
102226.167.3.40/29226.167.3.41 to 226.167.3.46226.167.3.476
103226.167.3.48/29226.167.3.49 to 226.167.3.54226.167.3.556
104226.167.3.56/29226.167.3.57 to 226.167.3.62226.167.3.636
105226.167.3.64/29226.167.3.65 to 226.167.3.70226.167.3.716
106226.167.3.72/29226.167.3.73 to 226.167.3.78226.167.3.796
107226.167.3.80/29226.167.3.81 to 226.167.3.86226.167.3.876
108226.167.3.88/29226.167.3.89 to 226.167.3.94226.167.3.956
109226.167.3.96/29226.167.3.97 to 226.167.3.102226.167.3.1036
110226.167.3.104/29226.167.3.105 to 226.167.3.110226.167.3.1116
111226.167.3.112/29226.167.3.113 to 226.167.3.118226.167.3.1196
112226.167.3.120/29226.167.3.121 to 226.167.3.126226.167.3.1276
113226.167.3.128/29226.167.3.129 to 226.167.3.134226.167.3.1356
114226.167.3.136/29226.167.3.137 to 226.167.3.142226.167.3.1436
115226.167.3.144/29226.167.3.145 to 226.167.3.150226.167.3.1516
116226.167.3.152/29226.167.3.153 to 226.167.3.158226.167.3.1596
117226.167.3.160/29226.167.3.161 to 226.167.3.166226.167.3.1676
118226.167.3.168/29226.167.3.169 to 226.167.3.174226.167.3.1756
119226.167.3.176/29226.167.3.177 to 226.167.3.182226.167.3.1836
120226.167.3.184/29226.167.3.185 to 226.167.3.190226.167.3.1916
121226.167.3.192/29226.167.3.193 to 226.167.3.198226.167.3.1996
122226.167.3.200/29226.167.3.201 to 226.167.3.206226.167.3.2076
123226.167.3.208/29226.167.3.209 to 226.167.3.214226.167.3.2156
124226.167.3.216/29226.167.3.217 to 226.167.3.222226.167.3.2236
125226.167.3.224/29226.167.3.225 to 226.167.3.230226.167.3.2316
126226.167.3.232/29226.167.3.233 to 226.167.3.238226.167.3.2396
127226.167.3.240/29226.167.3.241 to 226.167.3.246226.167.3.2476
128226.167.3.248/29226.167.3.249 to 226.167.3.254226.167.3.2556
129226.167.4.0/29226.167.4.1 to 226.167.4.6226.167.4.76
130226.167.4.8/29226.167.4.9 to 226.167.4.14226.167.4.156
131226.167.4.16/29226.167.4.17 to 226.167.4.22226.167.4.236
132226.167.4.24/29226.167.4.25 to 226.167.4.30226.167.4.316
133226.167.4.32/29226.167.4.33 to 226.167.4.38226.167.4.396
134226.167.4.40/29226.167.4.41 to 226.167.4.46226.167.4.476
135226.167.4.48/29226.167.4.49 to 226.167.4.54226.167.4.556
136226.167.4.56/29226.167.4.57 to 226.167.4.62226.167.4.636
137226.167.4.64/29226.167.4.65 to 226.167.4.70226.167.4.716
138226.167.4.72/29226.167.4.73 to 226.167.4.78226.167.4.796
139226.167.4.80/29226.167.4.81 to 226.167.4.86226.167.4.876
140226.167.4.88/29226.167.4.89 to 226.167.4.94226.167.4.956
141226.167.4.96/29226.167.4.97 to 226.167.4.102226.167.4.1036
142226.167.4.104/29226.167.4.105 to 226.167.4.110226.167.4.1116
143226.167.4.112/29226.167.4.113 to 226.167.4.118226.167.4.1196
144226.167.4.120/29226.167.4.121 to 226.167.4.126226.167.4.1276
145226.167.4.128/29226.167.4.129 to 226.167.4.134226.167.4.1356
146226.167.4.136/29226.167.4.137 to 226.167.4.142226.167.4.1436
147226.167.4.144/29226.167.4.145 to 226.167.4.150226.167.4.1516
148226.167.4.152/29226.167.4.153 to 226.167.4.158226.167.4.1596
149226.167.4.160/29226.167.4.161 to 226.167.4.166226.167.4.1676
150226.167.4.168/29226.167.4.169 to 226.167.4.174226.167.4.1756
151226.167.4.176/29226.167.4.177 to 226.167.4.182226.167.4.1836
152226.167.4.184/29226.167.4.185 to 226.167.4.190226.167.4.1916
153226.167.4.192/29226.167.4.193 to 226.167.4.198226.167.4.1996
154226.167.4.200/29226.167.4.201 to 226.167.4.206226.167.4.2076
155226.167.4.208/29226.167.4.209 to 226.167.4.214226.167.4.2156
156226.167.4.216/29226.167.4.217 to 226.167.4.222226.167.4.2236
157226.167.4.224/29226.167.4.225 to 226.167.4.230226.167.4.2316
158226.167.4.232/29226.167.4.233 to 226.167.4.238226.167.4.2396
159226.167.4.240/29226.167.4.241 to 226.167.4.246226.167.4.2476
160226.167.4.248/29226.167.4.249 to 226.167.4.254226.167.4.2556
161226.167.5.0/29226.167.5.1 to 226.167.5.6226.167.5.76
162226.167.5.8/29226.167.5.9 to 226.167.5.14226.167.5.156
163226.167.5.16/29226.167.5.17 to 226.167.5.22226.167.5.236
164226.167.5.24/29226.167.5.25 to 226.167.5.30226.167.5.316
165226.167.5.32/29226.167.5.33 to 226.167.5.38226.167.5.396
166226.167.5.40/29226.167.5.41 to 226.167.5.46226.167.5.476
167226.167.5.48/29226.167.5.49 to 226.167.5.54226.167.5.556
168226.167.5.56/29226.167.5.57 to 226.167.5.62226.167.5.636
169226.167.5.64/29226.167.5.65 to 226.167.5.70226.167.5.716
170226.167.5.72/29226.167.5.73 to 226.167.5.78226.167.5.796
171226.167.5.80/29226.167.5.81 to 226.167.5.86226.167.5.876
172226.167.5.88/29226.167.5.89 to 226.167.5.94226.167.5.956
173226.167.5.96/29226.167.5.97 to 226.167.5.102226.167.5.1036
174226.167.5.104/29226.167.5.105 to 226.167.5.110226.167.5.1116
175226.167.5.112/29226.167.5.113 to 226.167.5.118226.167.5.1196
176226.167.5.120/29226.167.5.121 to 226.167.5.126226.167.5.1276
177226.167.5.128/29226.167.5.129 to 226.167.5.134226.167.5.1356
178226.167.5.136/29226.167.5.137 to 226.167.5.142226.167.5.1436
179226.167.5.144/29226.167.5.145 to 226.167.5.150226.167.5.1516
180226.167.5.152/29226.167.5.153 to 226.167.5.158226.167.5.1596
181226.167.5.160/29226.167.5.161 to 226.167.5.166226.167.5.1676
182226.167.5.168/29226.167.5.169 to 226.167.5.174226.167.5.1756
183226.167.5.176/29226.167.5.177 to 226.167.5.182226.167.5.1836
184226.167.5.184/29226.167.5.185 to 226.167.5.190226.167.5.1916
185226.167.5.192/29226.167.5.193 to 226.167.5.198226.167.5.1996
186226.167.5.200/29226.167.5.201 to 226.167.5.206226.167.5.2076
187226.167.5.208/29226.167.5.209 to 226.167.5.214226.167.5.2156
188226.167.5.216/29226.167.5.217 to 226.167.5.222226.167.5.2236
189226.167.5.224/29226.167.5.225 to 226.167.5.230226.167.5.2316
190226.167.5.232/29226.167.5.233 to 226.167.5.238226.167.5.2396
191226.167.5.240/29226.167.5.241 to 226.167.5.246226.167.5.2476
192226.167.5.248/29226.167.5.249 to 226.167.5.254226.167.5.2556
193226.167.6.0/29226.167.6.1 to 226.167.6.6226.167.6.76
194226.167.6.8/29226.167.6.9 to 226.167.6.14226.167.6.156
195226.167.6.16/29226.167.6.17 to 226.167.6.22226.167.6.236
196226.167.6.24/29226.167.6.25 to 226.167.6.30226.167.6.316
197226.167.6.32/29226.167.6.33 to 226.167.6.38226.167.6.396
198226.167.6.40/29226.167.6.41 to 226.167.6.46226.167.6.476
199226.167.6.48/29226.167.6.49 to 226.167.6.54226.167.6.556
200226.167.6.56/29226.167.6.57 to 226.167.6.62226.167.6.636
201226.167.6.64/29226.167.6.65 to 226.167.6.70226.167.6.716
202226.167.6.72/29226.167.6.73 to 226.167.6.78226.167.6.796
203226.167.6.80/29226.167.6.81 to 226.167.6.86226.167.6.876
204226.167.6.88/29226.167.6.89 to 226.167.6.94226.167.6.956
205226.167.6.96/29226.167.6.97 to 226.167.6.102226.167.6.1036
206226.167.6.104/29226.167.6.105 to 226.167.6.110226.167.6.1116
207226.167.6.112/29226.167.6.113 to 226.167.6.118226.167.6.1196
208226.167.6.120/29226.167.6.121 to 226.167.6.126226.167.6.1276
209226.167.6.128/29226.167.6.129 to 226.167.6.134226.167.6.1356
210226.167.6.136/29226.167.6.137 to 226.167.6.142226.167.6.1436
211226.167.6.144/29226.167.6.145 to 226.167.6.150226.167.6.1516
212226.167.6.152/29226.167.6.153 to 226.167.6.158226.167.6.1596
213226.167.6.160/29226.167.6.161 to 226.167.6.166226.167.6.1676
214226.167.6.168/29226.167.6.169 to 226.167.6.174226.167.6.1756
215226.167.6.176/29226.167.6.177 to 226.167.6.182226.167.6.1836
216226.167.6.184/29226.167.6.185 to 226.167.6.190226.167.6.1916
217226.167.6.192/29226.167.6.193 to 226.167.6.198226.167.6.1996
218226.167.6.200/29226.167.6.201 to 226.167.6.206226.167.6.2076
219226.167.6.208/29226.167.6.209 to 226.167.6.214226.167.6.2156
220226.167.6.216/29226.167.6.217 to 226.167.6.222226.167.6.2236
221226.167.6.224/29226.167.6.225 to 226.167.6.230226.167.6.2316
222226.167.6.232/29226.167.6.233 to 226.167.6.238226.167.6.2396
223226.167.6.240/29226.167.6.241 to 226.167.6.246226.167.6.2476
224226.167.6.248/29226.167.6.249 to 226.167.6.254226.167.6.2556
225226.167.7.0/29226.167.7.1 to 226.167.7.6226.167.7.76
226226.167.7.8/29226.167.7.9 to 226.167.7.14226.167.7.156
227226.167.7.16/29226.167.7.17 to 226.167.7.22226.167.7.236
228226.167.7.24/29226.167.7.25 to 226.167.7.30226.167.7.316
229226.167.7.32/29226.167.7.33 to 226.167.7.38226.167.7.396
230226.167.7.40/29226.167.7.41 to 226.167.7.46226.167.7.476
231226.167.7.48/29226.167.7.49 to 226.167.7.54226.167.7.556
232226.167.7.56/29226.167.7.57 to 226.167.7.62226.167.7.636
233226.167.7.64/29226.167.7.65 to 226.167.7.70226.167.7.716
234226.167.7.72/29226.167.7.73 to 226.167.7.78226.167.7.796
235226.167.7.80/29226.167.7.81 to 226.167.7.86226.167.7.876
236226.167.7.88/29226.167.7.89 to 226.167.7.94226.167.7.956
237226.167.7.96/29226.167.7.97 to 226.167.7.102226.167.7.1036
238226.167.7.104/29226.167.7.105 to 226.167.7.110226.167.7.1116
239226.167.7.112/29226.167.7.113 to 226.167.7.118226.167.7.1196
240226.167.7.120/29226.167.7.121 to 226.167.7.126226.167.7.1276
241226.167.7.128/29226.167.7.129 to 226.167.7.134226.167.7.1356
242226.167.7.136/29226.167.7.137 to 226.167.7.142226.167.7.1436
243226.167.7.144/29226.167.7.145 to 226.167.7.150226.167.7.1516
244226.167.7.152/29226.167.7.153 to 226.167.7.158226.167.7.1596
245226.167.7.160/29226.167.7.161 to 226.167.7.166226.167.7.1676
246226.167.7.168/29226.167.7.169 to 226.167.7.174226.167.7.1756
247226.167.7.176/29226.167.7.177 to 226.167.7.182226.167.7.1836
248226.167.7.184/29226.167.7.185 to 226.167.7.190226.167.7.1916
249226.167.7.192/29226.167.7.193 to 226.167.7.198226.167.7.1996
250226.167.7.200/29226.167.7.201 to 226.167.7.206226.167.7.2076
251226.167.7.208/29226.167.7.209 to 226.167.7.214226.167.7.2156
252226.167.7.216/29226.167.7.217 to 226.167.7.222226.167.7.2236
253226.167.7.224/29226.167.7.225 to 226.167.7.230226.167.7.2316
254226.167.7.232/29226.167.7.233 to 226.167.7.238226.167.7.2396
255226.167.7.240/29226.167.7.241 to 226.167.7.246226.167.7.2476
256226.167.7.248/29226.167.7.249 to 226.167.7.254226.167.7.2556

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.