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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.

Network249.167.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
249.167.0.0
Broadcast address
249.167.127.255
First usable
249.167.0.1
Last usable
249.167.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F9A70000 · Integer 4188471296 to 4188504063
Reverse DNS zones
0.167.249.in-addr.arpa
1.167.249.in-addr.arpa
2.167.249.in-addr.arpa
3.167.249.in-addr.arpa
4.167.249.in-addr.arpa
5.167.249.in-addr.arpa
6.167.249.in-addr.arpa
7.167.249.in-addr.arpa
8.167.249.in-addr.arpa
9.167.249.in-addr.arpa
10.167.249.in-addr.arpa
11.167.249.in-addr.arpa
12.167.249.in-addr.arpa
13.167.249.in-addr.arpa
14.167.249.in-addr.arpa
15.167.249.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111001.10100111.00000000.00000000249.167.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network11111001.10100111.00000000.00000000249.167.0.0
Broadcast11111001.10100111.01111111.11111111249.167.127.255
Split into smaller subnets/28
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

249.167.0.0/17 makes 2,048 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1249.167.0.0/28249.167.0.1 to 249.167.0.14249.167.0.1514
2249.167.0.16/28249.167.0.17 to 249.167.0.30249.167.0.3114
3249.167.0.32/28249.167.0.33 to 249.167.0.46249.167.0.4714
4249.167.0.48/28249.167.0.49 to 249.167.0.62249.167.0.6314
5249.167.0.64/28249.167.0.65 to 249.167.0.78249.167.0.7914
6249.167.0.80/28249.167.0.81 to 249.167.0.94249.167.0.9514
7249.167.0.96/28249.167.0.97 to 249.167.0.110249.167.0.11114
8249.167.0.112/28249.167.0.113 to 249.167.0.126249.167.0.12714
9249.167.0.128/28249.167.0.129 to 249.167.0.142249.167.0.14314
10249.167.0.144/28249.167.0.145 to 249.167.0.158249.167.0.15914
11249.167.0.160/28249.167.0.161 to 249.167.0.174249.167.0.17514
12249.167.0.176/28249.167.0.177 to 249.167.0.190249.167.0.19114
13249.167.0.192/28249.167.0.193 to 249.167.0.206249.167.0.20714
14249.167.0.208/28249.167.0.209 to 249.167.0.222249.167.0.22314
15249.167.0.224/28249.167.0.225 to 249.167.0.238249.167.0.23914
16249.167.0.240/28249.167.0.241 to 249.167.0.254249.167.0.25514
17249.167.1.0/28249.167.1.1 to 249.167.1.14249.167.1.1514
18249.167.1.16/28249.167.1.17 to 249.167.1.30249.167.1.3114
19249.167.1.32/28249.167.1.33 to 249.167.1.46249.167.1.4714
20249.167.1.48/28249.167.1.49 to 249.167.1.62249.167.1.6314
21249.167.1.64/28249.167.1.65 to 249.167.1.78249.167.1.7914
22249.167.1.80/28249.167.1.81 to 249.167.1.94249.167.1.9514
23249.167.1.96/28249.167.1.97 to 249.167.1.110249.167.1.11114
24249.167.1.112/28249.167.1.113 to 249.167.1.126249.167.1.12714
25249.167.1.128/28249.167.1.129 to 249.167.1.142249.167.1.14314
26249.167.1.144/28249.167.1.145 to 249.167.1.158249.167.1.15914
27249.167.1.160/28249.167.1.161 to 249.167.1.174249.167.1.17514
28249.167.1.176/28249.167.1.177 to 249.167.1.190249.167.1.19114
29249.167.1.192/28249.167.1.193 to 249.167.1.206249.167.1.20714
30249.167.1.208/28249.167.1.209 to 249.167.1.222249.167.1.22314
31249.167.1.224/28249.167.1.225 to 249.167.1.238249.167.1.23914
32249.167.1.240/28249.167.1.241 to 249.167.1.254249.167.1.25514
33249.167.2.0/28249.167.2.1 to 249.167.2.14249.167.2.1514
34249.167.2.16/28249.167.2.17 to 249.167.2.30249.167.2.3114
35249.167.2.32/28249.167.2.33 to 249.167.2.46249.167.2.4714
36249.167.2.48/28249.167.2.49 to 249.167.2.62249.167.2.6314
37249.167.2.64/28249.167.2.65 to 249.167.2.78249.167.2.7914
38249.167.2.80/28249.167.2.81 to 249.167.2.94249.167.2.9514
39249.167.2.96/28249.167.2.97 to 249.167.2.110249.167.2.11114
40249.167.2.112/28249.167.2.113 to 249.167.2.126249.167.2.12714
41249.167.2.128/28249.167.2.129 to 249.167.2.142249.167.2.14314
42249.167.2.144/28249.167.2.145 to 249.167.2.158249.167.2.15914
43249.167.2.160/28249.167.2.161 to 249.167.2.174249.167.2.17514
44249.167.2.176/28249.167.2.177 to 249.167.2.190249.167.2.19114
45249.167.2.192/28249.167.2.193 to 249.167.2.206249.167.2.20714
46249.167.2.208/28249.167.2.209 to 249.167.2.222249.167.2.22314
47249.167.2.224/28249.167.2.225 to 249.167.2.238249.167.2.23914
48249.167.2.240/28249.167.2.241 to 249.167.2.254249.167.2.25514
49249.167.3.0/28249.167.3.1 to 249.167.3.14249.167.3.1514
50249.167.3.16/28249.167.3.17 to 249.167.3.30249.167.3.3114
51249.167.3.32/28249.167.3.33 to 249.167.3.46249.167.3.4714
52249.167.3.48/28249.167.3.49 to 249.167.3.62249.167.3.6314
53249.167.3.64/28249.167.3.65 to 249.167.3.78249.167.3.7914
54249.167.3.80/28249.167.3.81 to 249.167.3.94249.167.3.9514
55249.167.3.96/28249.167.3.97 to 249.167.3.110249.167.3.11114
56249.167.3.112/28249.167.3.113 to 249.167.3.126249.167.3.12714
57249.167.3.128/28249.167.3.129 to 249.167.3.142249.167.3.14314
58249.167.3.144/28249.167.3.145 to 249.167.3.158249.167.3.15914
59249.167.3.160/28249.167.3.161 to 249.167.3.174249.167.3.17514
60249.167.3.176/28249.167.3.177 to 249.167.3.190249.167.3.19114
61249.167.3.192/28249.167.3.193 to 249.167.3.206249.167.3.20714
62249.167.3.208/28249.167.3.209 to 249.167.3.222249.167.3.22314
63249.167.3.224/28249.167.3.225 to 249.167.3.238249.167.3.23914
64249.167.3.240/28249.167.3.241 to 249.167.3.254249.167.3.25514
65249.167.4.0/28249.167.4.1 to 249.167.4.14249.167.4.1514
66249.167.4.16/28249.167.4.17 to 249.167.4.30249.167.4.3114
67249.167.4.32/28249.167.4.33 to 249.167.4.46249.167.4.4714
68249.167.4.48/28249.167.4.49 to 249.167.4.62249.167.4.6314
69249.167.4.64/28249.167.4.65 to 249.167.4.78249.167.4.7914
70249.167.4.80/28249.167.4.81 to 249.167.4.94249.167.4.9514
71249.167.4.96/28249.167.4.97 to 249.167.4.110249.167.4.11114
72249.167.4.112/28249.167.4.113 to 249.167.4.126249.167.4.12714
73249.167.4.128/28249.167.4.129 to 249.167.4.142249.167.4.14314
74249.167.4.144/28249.167.4.145 to 249.167.4.158249.167.4.15914
75249.167.4.160/28249.167.4.161 to 249.167.4.174249.167.4.17514
76249.167.4.176/28249.167.4.177 to 249.167.4.190249.167.4.19114
77249.167.4.192/28249.167.4.193 to 249.167.4.206249.167.4.20714
78249.167.4.208/28249.167.4.209 to 249.167.4.222249.167.4.22314
79249.167.4.224/28249.167.4.225 to 249.167.4.238249.167.4.23914
80249.167.4.240/28249.167.4.241 to 249.167.4.254249.167.4.25514
81249.167.5.0/28249.167.5.1 to 249.167.5.14249.167.5.1514
82249.167.5.16/28249.167.5.17 to 249.167.5.30249.167.5.3114
83249.167.5.32/28249.167.5.33 to 249.167.5.46249.167.5.4714
84249.167.5.48/28249.167.5.49 to 249.167.5.62249.167.5.6314
85249.167.5.64/28249.167.5.65 to 249.167.5.78249.167.5.7914
86249.167.5.80/28249.167.5.81 to 249.167.5.94249.167.5.9514
87249.167.5.96/28249.167.5.97 to 249.167.5.110249.167.5.11114
88249.167.5.112/28249.167.5.113 to 249.167.5.126249.167.5.12714
89249.167.5.128/28249.167.5.129 to 249.167.5.142249.167.5.14314
90249.167.5.144/28249.167.5.145 to 249.167.5.158249.167.5.15914
91249.167.5.160/28249.167.5.161 to 249.167.5.174249.167.5.17514
92249.167.5.176/28249.167.5.177 to 249.167.5.190249.167.5.19114
93249.167.5.192/28249.167.5.193 to 249.167.5.206249.167.5.20714
94249.167.5.208/28249.167.5.209 to 249.167.5.222249.167.5.22314
95249.167.5.224/28249.167.5.225 to 249.167.5.238249.167.5.23914
96249.167.5.240/28249.167.5.241 to 249.167.5.254249.167.5.25514
97249.167.6.0/28249.167.6.1 to 249.167.6.14249.167.6.1514
98249.167.6.16/28249.167.6.17 to 249.167.6.30249.167.6.3114
99249.167.6.32/28249.167.6.33 to 249.167.6.46249.167.6.4714
100249.167.6.48/28249.167.6.49 to 249.167.6.62249.167.6.6314
101249.167.6.64/28249.167.6.65 to 249.167.6.78249.167.6.7914
102249.167.6.80/28249.167.6.81 to 249.167.6.94249.167.6.9514
103249.167.6.96/28249.167.6.97 to 249.167.6.110249.167.6.11114
104249.167.6.112/28249.167.6.113 to 249.167.6.126249.167.6.12714
105249.167.6.128/28249.167.6.129 to 249.167.6.142249.167.6.14314
106249.167.6.144/28249.167.6.145 to 249.167.6.158249.167.6.15914
107249.167.6.160/28249.167.6.161 to 249.167.6.174249.167.6.17514
108249.167.6.176/28249.167.6.177 to 249.167.6.190249.167.6.19114
109249.167.6.192/28249.167.6.193 to 249.167.6.206249.167.6.20714
110249.167.6.208/28249.167.6.209 to 249.167.6.222249.167.6.22314
111249.167.6.224/28249.167.6.225 to 249.167.6.238249.167.6.23914
112249.167.6.240/28249.167.6.241 to 249.167.6.254249.167.6.25514
113249.167.7.0/28249.167.7.1 to 249.167.7.14249.167.7.1514
114249.167.7.16/28249.167.7.17 to 249.167.7.30249.167.7.3114
115249.167.7.32/28249.167.7.33 to 249.167.7.46249.167.7.4714
116249.167.7.48/28249.167.7.49 to 249.167.7.62249.167.7.6314
117249.167.7.64/28249.167.7.65 to 249.167.7.78249.167.7.7914
118249.167.7.80/28249.167.7.81 to 249.167.7.94249.167.7.9514
119249.167.7.96/28249.167.7.97 to 249.167.7.110249.167.7.11114
120249.167.7.112/28249.167.7.113 to 249.167.7.126249.167.7.12714
121249.167.7.128/28249.167.7.129 to 249.167.7.142249.167.7.14314
122249.167.7.144/28249.167.7.145 to 249.167.7.158249.167.7.15914
123249.167.7.160/28249.167.7.161 to 249.167.7.174249.167.7.17514
124249.167.7.176/28249.167.7.177 to 249.167.7.190249.167.7.19114
125249.167.7.192/28249.167.7.193 to 249.167.7.206249.167.7.20714
126249.167.7.208/28249.167.7.209 to 249.167.7.222249.167.7.22314
127249.167.7.224/28249.167.7.225 to 249.167.7.238249.167.7.23914
128249.167.7.240/28249.167.7.241 to 249.167.7.254249.167.7.25514
129249.167.8.0/28249.167.8.1 to 249.167.8.14249.167.8.1514
130249.167.8.16/28249.167.8.17 to 249.167.8.30249.167.8.3114
131249.167.8.32/28249.167.8.33 to 249.167.8.46249.167.8.4714
132249.167.8.48/28249.167.8.49 to 249.167.8.62249.167.8.6314
133249.167.8.64/28249.167.8.65 to 249.167.8.78249.167.8.7914
134249.167.8.80/28249.167.8.81 to 249.167.8.94249.167.8.9514
135249.167.8.96/28249.167.8.97 to 249.167.8.110249.167.8.11114
136249.167.8.112/28249.167.8.113 to 249.167.8.126249.167.8.12714
137249.167.8.128/28249.167.8.129 to 249.167.8.142249.167.8.14314
138249.167.8.144/28249.167.8.145 to 249.167.8.158249.167.8.15914
139249.167.8.160/28249.167.8.161 to 249.167.8.174249.167.8.17514
140249.167.8.176/28249.167.8.177 to 249.167.8.190249.167.8.19114
141249.167.8.192/28249.167.8.193 to 249.167.8.206249.167.8.20714
142249.167.8.208/28249.167.8.209 to 249.167.8.222249.167.8.22314
143249.167.8.224/28249.167.8.225 to 249.167.8.238249.167.8.23914
144249.167.8.240/28249.167.8.241 to 249.167.8.254249.167.8.25514
145249.167.9.0/28249.167.9.1 to 249.167.9.14249.167.9.1514
146249.167.9.16/28249.167.9.17 to 249.167.9.30249.167.9.3114
147249.167.9.32/28249.167.9.33 to 249.167.9.46249.167.9.4714
148249.167.9.48/28249.167.9.49 to 249.167.9.62249.167.9.6314
149249.167.9.64/28249.167.9.65 to 249.167.9.78249.167.9.7914
150249.167.9.80/28249.167.9.81 to 249.167.9.94249.167.9.9514
151249.167.9.96/28249.167.9.97 to 249.167.9.110249.167.9.11114
152249.167.9.112/28249.167.9.113 to 249.167.9.126249.167.9.12714
153249.167.9.128/28249.167.9.129 to 249.167.9.142249.167.9.14314
154249.167.9.144/28249.167.9.145 to 249.167.9.158249.167.9.15914
155249.167.9.160/28249.167.9.161 to 249.167.9.174249.167.9.17514
156249.167.9.176/28249.167.9.177 to 249.167.9.190249.167.9.19114
157249.167.9.192/28249.167.9.193 to 249.167.9.206249.167.9.20714
158249.167.9.208/28249.167.9.209 to 249.167.9.222249.167.9.22314
159249.167.9.224/28249.167.9.225 to 249.167.9.238249.167.9.23914
160249.167.9.240/28249.167.9.241 to 249.167.9.254249.167.9.25514
161249.167.10.0/28249.167.10.1 to 249.167.10.14249.167.10.1514
162249.167.10.16/28249.167.10.17 to 249.167.10.30249.167.10.3114
163249.167.10.32/28249.167.10.33 to 249.167.10.46249.167.10.4714
164249.167.10.48/28249.167.10.49 to 249.167.10.62249.167.10.6314
165249.167.10.64/28249.167.10.65 to 249.167.10.78249.167.10.7914
166249.167.10.80/28249.167.10.81 to 249.167.10.94249.167.10.9514
167249.167.10.96/28249.167.10.97 to 249.167.10.110249.167.10.11114
168249.167.10.112/28249.167.10.113 to 249.167.10.126249.167.10.12714
169249.167.10.128/28249.167.10.129 to 249.167.10.142249.167.10.14314
170249.167.10.144/28249.167.10.145 to 249.167.10.158249.167.10.15914
171249.167.10.160/28249.167.10.161 to 249.167.10.174249.167.10.17514
172249.167.10.176/28249.167.10.177 to 249.167.10.190249.167.10.19114
173249.167.10.192/28249.167.10.193 to 249.167.10.206249.167.10.20714
174249.167.10.208/28249.167.10.209 to 249.167.10.222249.167.10.22314
175249.167.10.224/28249.167.10.225 to 249.167.10.238249.167.10.23914
176249.167.10.240/28249.167.10.241 to 249.167.10.254249.167.10.25514
177249.167.11.0/28249.167.11.1 to 249.167.11.14249.167.11.1514
178249.167.11.16/28249.167.11.17 to 249.167.11.30249.167.11.3114
179249.167.11.32/28249.167.11.33 to 249.167.11.46249.167.11.4714
180249.167.11.48/28249.167.11.49 to 249.167.11.62249.167.11.6314
181249.167.11.64/28249.167.11.65 to 249.167.11.78249.167.11.7914
182249.167.11.80/28249.167.11.81 to 249.167.11.94249.167.11.9514
183249.167.11.96/28249.167.11.97 to 249.167.11.110249.167.11.11114
184249.167.11.112/28249.167.11.113 to 249.167.11.126249.167.11.12714
185249.167.11.128/28249.167.11.129 to 249.167.11.142249.167.11.14314
186249.167.11.144/28249.167.11.145 to 249.167.11.158249.167.11.15914
187249.167.11.160/28249.167.11.161 to 249.167.11.174249.167.11.17514
188249.167.11.176/28249.167.11.177 to 249.167.11.190249.167.11.19114
189249.167.11.192/28249.167.11.193 to 249.167.11.206249.167.11.20714
190249.167.11.208/28249.167.11.209 to 249.167.11.222249.167.11.22314
191249.167.11.224/28249.167.11.225 to 249.167.11.238249.167.11.23914
192249.167.11.240/28249.167.11.241 to 249.167.11.254249.167.11.25514
193249.167.12.0/28249.167.12.1 to 249.167.12.14249.167.12.1514
194249.167.12.16/28249.167.12.17 to 249.167.12.30249.167.12.3114
195249.167.12.32/28249.167.12.33 to 249.167.12.46249.167.12.4714
196249.167.12.48/28249.167.12.49 to 249.167.12.62249.167.12.6314
197249.167.12.64/28249.167.12.65 to 249.167.12.78249.167.12.7914
198249.167.12.80/28249.167.12.81 to 249.167.12.94249.167.12.9514
199249.167.12.96/28249.167.12.97 to 249.167.12.110249.167.12.11114
200249.167.12.112/28249.167.12.113 to 249.167.12.126249.167.12.12714
201249.167.12.128/28249.167.12.129 to 249.167.12.142249.167.12.14314
202249.167.12.144/28249.167.12.145 to 249.167.12.158249.167.12.15914
203249.167.12.160/28249.167.12.161 to 249.167.12.174249.167.12.17514
204249.167.12.176/28249.167.12.177 to 249.167.12.190249.167.12.19114
205249.167.12.192/28249.167.12.193 to 249.167.12.206249.167.12.20714
206249.167.12.208/28249.167.12.209 to 249.167.12.222249.167.12.22314
207249.167.12.224/28249.167.12.225 to 249.167.12.238249.167.12.23914
208249.167.12.240/28249.167.12.241 to 249.167.12.254249.167.12.25514
209249.167.13.0/28249.167.13.1 to 249.167.13.14249.167.13.1514
210249.167.13.16/28249.167.13.17 to 249.167.13.30249.167.13.3114
211249.167.13.32/28249.167.13.33 to 249.167.13.46249.167.13.4714
212249.167.13.48/28249.167.13.49 to 249.167.13.62249.167.13.6314
213249.167.13.64/28249.167.13.65 to 249.167.13.78249.167.13.7914
214249.167.13.80/28249.167.13.81 to 249.167.13.94249.167.13.9514
215249.167.13.96/28249.167.13.97 to 249.167.13.110249.167.13.11114
216249.167.13.112/28249.167.13.113 to 249.167.13.126249.167.13.12714
217249.167.13.128/28249.167.13.129 to 249.167.13.142249.167.13.14314
218249.167.13.144/28249.167.13.145 to 249.167.13.158249.167.13.15914
219249.167.13.160/28249.167.13.161 to 249.167.13.174249.167.13.17514
220249.167.13.176/28249.167.13.177 to 249.167.13.190249.167.13.19114
221249.167.13.192/28249.167.13.193 to 249.167.13.206249.167.13.20714
222249.167.13.208/28249.167.13.209 to 249.167.13.222249.167.13.22314
223249.167.13.224/28249.167.13.225 to 249.167.13.238249.167.13.23914
224249.167.13.240/28249.167.13.241 to 249.167.13.254249.167.13.25514
225249.167.14.0/28249.167.14.1 to 249.167.14.14249.167.14.1514
226249.167.14.16/28249.167.14.17 to 249.167.14.30249.167.14.3114
227249.167.14.32/28249.167.14.33 to 249.167.14.46249.167.14.4714
228249.167.14.48/28249.167.14.49 to 249.167.14.62249.167.14.6314
229249.167.14.64/28249.167.14.65 to 249.167.14.78249.167.14.7914
230249.167.14.80/28249.167.14.81 to 249.167.14.94249.167.14.9514
231249.167.14.96/28249.167.14.97 to 249.167.14.110249.167.14.11114
232249.167.14.112/28249.167.14.113 to 249.167.14.126249.167.14.12714
233249.167.14.128/28249.167.14.129 to 249.167.14.142249.167.14.14314
234249.167.14.144/28249.167.14.145 to 249.167.14.158249.167.14.15914
235249.167.14.160/28249.167.14.161 to 249.167.14.174249.167.14.17514
236249.167.14.176/28249.167.14.177 to 249.167.14.190249.167.14.19114
237249.167.14.192/28249.167.14.193 to 249.167.14.206249.167.14.20714
238249.167.14.208/28249.167.14.209 to 249.167.14.222249.167.14.22314
239249.167.14.224/28249.167.14.225 to 249.167.14.238249.167.14.23914
240249.167.14.240/28249.167.14.241 to 249.167.14.254249.167.14.25514
241249.167.15.0/28249.167.15.1 to 249.167.15.14249.167.15.1514
242249.167.15.16/28249.167.15.17 to 249.167.15.30249.167.15.3114
243249.167.15.32/28249.167.15.33 to 249.167.15.46249.167.15.4714
244249.167.15.48/28249.167.15.49 to 249.167.15.62249.167.15.6314
245249.167.15.64/28249.167.15.65 to 249.167.15.78249.167.15.7914
246249.167.15.80/28249.167.15.81 to 249.167.15.94249.167.15.9514
247249.167.15.96/28249.167.15.97 to 249.167.15.110249.167.15.11114
248249.167.15.112/28249.167.15.113 to 249.167.15.126249.167.15.12714
249249.167.15.128/28249.167.15.129 to 249.167.15.142249.167.15.14314
250249.167.15.144/28249.167.15.145 to 249.167.15.158249.167.15.15914
251249.167.15.160/28249.167.15.161 to 249.167.15.174249.167.15.17514
252249.167.15.176/28249.167.15.177 to 249.167.15.190249.167.15.19114
253249.167.15.192/28249.167.15.193 to 249.167.15.206249.167.15.20714
254249.167.15.208/28249.167.15.209 to 249.167.15.222249.167.15.22314
255249.167.15.224/28249.167.15.225 to 249.167.15.238249.167.15.23914
256249.167.15.240/28249.167.15.241 to 249.167.15.254249.167.15.25514

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.