ip
ipku.in

IPv4 Subnet Calculator

Enter an IP with a CIDR prefix or a subnet mask to see its network, broadcast, host range, and host count. You can also split the network into smaller subnets.

$ ipcalc
Try:192.168.1.10/2410.0.0.0/8172.16.5.4/20203.0.113.9/29
IPv6 calculator →
private IP (RFC 1918)172.16.12.128/25
network172.16.12.128/25
broadcast172.16.12.255
first host172.16.12.129
last host172.16.12.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classB
ipcalc 172.16.12.128/25
address10101100.00010000.00001100.10000000
subnet mask11111111.11111111.11111111.10000000
network10101100.00010000.00001100.10000000
broadcast10101100.00010000.00001100.11111111
green = network part, grey = host part
hex0xac100c80
decimal2886732928
reverse dns128.12.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:c80

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
1172.16.12.128/31172.16.12.128 – 172.16.12.129172.16.12.129
2172.16.12.130/31172.16.12.130 – 172.16.12.131172.16.12.131
3172.16.12.132/31172.16.12.132 – 172.16.12.133172.16.12.133
4172.16.12.134/31172.16.12.134 – 172.16.12.135172.16.12.135
5172.16.12.136/31172.16.12.136 – 172.16.12.137172.16.12.137
6172.16.12.138/31172.16.12.138 – 172.16.12.139172.16.12.139
7172.16.12.140/31172.16.12.140 – 172.16.12.141172.16.12.141
8172.16.12.142/31172.16.12.142 – 172.16.12.143172.16.12.143
9172.16.12.144/31172.16.12.144 – 172.16.12.145172.16.12.145
10172.16.12.146/31172.16.12.146 – 172.16.12.147172.16.12.147
11172.16.12.148/31172.16.12.148 – 172.16.12.149172.16.12.149
12172.16.12.150/31172.16.12.150 – 172.16.12.151172.16.12.151
13172.16.12.152/31172.16.12.152 – 172.16.12.153172.16.12.153
14172.16.12.154/31172.16.12.154 – 172.16.12.155172.16.12.155
15172.16.12.156/31172.16.12.156 – 172.16.12.157172.16.12.157
16172.16.12.158/31172.16.12.158 – 172.16.12.159172.16.12.159
17172.16.12.160/31172.16.12.160 – 172.16.12.161172.16.12.161
18172.16.12.162/31172.16.12.162 – 172.16.12.163172.16.12.163
19172.16.12.164/31172.16.12.164 – 172.16.12.165172.16.12.165
20172.16.12.166/31172.16.12.166 – 172.16.12.167172.16.12.167
21172.16.12.168/31172.16.12.168 – 172.16.12.169172.16.12.169
22172.16.12.170/31172.16.12.170 – 172.16.12.171172.16.12.171
23172.16.12.172/31172.16.12.172 – 172.16.12.173172.16.12.173
24172.16.12.174/31172.16.12.174 – 172.16.12.175172.16.12.175
25172.16.12.176/31172.16.12.176 – 172.16.12.177172.16.12.177
26172.16.12.178/31172.16.12.178 – 172.16.12.179172.16.12.179
27172.16.12.180/31172.16.12.180 – 172.16.12.181172.16.12.181
28172.16.12.182/31172.16.12.182 – 172.16.12.183172.16.12.183
29172.16.12.184/31172.16.12.184 – 172.16.12.185172.16.12.185
30172.16.12.186/31172.16.12.186 – 172.16.12.187172.16.12.187
31172.16.12.188/31172.16.12.188 – 172.16.12.189172.16.12.189
32172.16.12.190/31172.16.12.190 – 172.16.12.191172.16.12.191
33172.16.12.192/31172.16.12.192 – 172.16.12.193172.16.12.193
34172.16.12.194/31172.16.12.194 – 172.16.12.195172.16.12.195
35172.16.12.196/31172.16.12.196 – 172.16.12.197172.16.12.197
36172.16.12.198/31172.16.12.198 – 172.16.12.199172.16.12.199
37172.16.12.200/31172.16.12.200 – 172.16.12.201172.16.12.201
38172.16.12.202/31172.16.12.202 – 172.16.12.203172.16.12.203
39172.16.12.204/31172.16.12.204 – 172.16.12.205172.16.12.205
40172.16.12.206/31172.16.12.206 – 172.16.12.207172.16.12.207
41172.16.12.208/31172.16.12.208 – 172.16.12.209172.16.12.209
42172.16.12.210/31172.16.12.210 – 172.16.12.211172.16.12.211
43172.16.12.212/31172.16.12.212 – 172.16.12.213172.16.12.213
44172.16.12.214/31172.16.12.214 – 172.16.12.215172.16.12.215
45172.16.12.216/31172.16.12.216 – 172.16.12.217172.16.12.217
46172.16.12.218/31172.16.12.218 – 172.16.12.219172.16.12.219
47172.16.12.220/31172.16.12.220 – 172.16.12.221172.16.12.221
48172.16.12.222/31172.16.12.222 – 172.16.12.223172.16.12.223
49172.16.12.224/31172.16.12.224 – 172.16.12.225172.16.12.225
50172.16.12.226/31172.16.12.226 – 172.16.12.227172.16.12.227
51172.16.12.228/31172.16.12.228 – 172.16.12.229172.16.12.229
52172.16.12.230/31172.16.12.230 – 172.16.12.231172.16.12.231
53172.16.12.232/31172.16.12.232 – 172.16.12.233172.16.12.233
54172.16.12.234/31172.16.12.234 – 172.16.12.235172.16.12.235
55172.16.12.236/31172.16.12.236 – 172.16.12.237172.16.12.237
56172.16.12.238/31172.16.12.238 – 172.16.12.239172.16.12.239
57172.16.12.240/31172.16.12.240 – 172.16.12.241172.16.12.241
58172.16.12.242/31172.16.12.242 – 172.16.12.243172.16.12.243
59172.16.12.244/31172.16.12.244 – 172.16.12.245172.16.12.245
60172.16.12.246/31172.16.12.246 – 172.16.12.247172.16.12.247
61172.16.12.248/31172.16.12.248 – 172.16.12.249172.16.12.249
62172.16.12.250/31172.16.12.250 – 172.16.12.251172.16.12.251
63172.16.12.252/31172.16.12.252 – 172.16.12.253172.16.12.253
64172.16.12.254/31172.16.12.254 – 172.16.12.255172.16.12.255
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /25
/00.0.0.04,294,967,2964,294,967,294-
/1128.0.0.02,147,483,6482,147,483,646-
/2192.0.0.01,073,741,8241,073,741,822-
/3224.0.0.0536,870,912536,870,910-
/4240.0.0.0268,435,456268,435,454-
/5248.0.0.0134,217,728134,217,726-
/6252.0.0.067,108,86467,108,862-
/7254.0.0.033,554,43233,554,430-
/8255.0.0.016,777,21616,777,214-
/9255.128.0.08,388,6088,388,606-
/10255.192.0.04,194,3044,194,302-
/11255.224.0.02,097,1522,097,150-
/12255.240.0.01,048,5761,048,574-
/13255.248.0.0524,288524,286-
/14255.252.0.0262,144262,142-
/15255.254.0.0131,072131,070-
/16255.255.0.065,53665,534-
/17255.255.128.032,76832,766-
/18255.255.192.016,38416,382-
/19255.255.224.08,1928,190-
/20255.255.240.04,0964,094-
/21255.255.248.02,0482,046-
/22255.255.252.01,0241,022-
/23255.255.254.0512510-
/24255.255.255.0256254-
/25255.255.255.1281281261
/26255.255.255.19264622 split →
/27255.255.255.22432304 split →
/28255.255.255.24016148 split →
/29255.255.255.2488616 split →
/30255.255.255.2524232 split →
/31255.255.255.2542264 split →
/32255.255.255.25511128 split →
02 / faq

About this calculator.

How do I use this subnet calculator?

▼

Type an IP address followed by a prefix, like 192.168.1.10/24, or by a subnet mask, like 192.168.1.10 255.255.255.0. Without a prefix it uses /24. Click a row in the table to split the network into smaller subnets.

Why are usable hosts always 2 fewer?

▼

The first address in a subnet is the network address and the last is the broadcast address, so neither can go to a device. The exceptions are /31 (point-to-point links, RFC 3021) and /32 (a single address), which use every address.

Can I use it from a terminal?

▼

Yes. curl 'ipku.in/en/tools/ipv4-subnet-calculator?q=192.168.1.10/24' returns the result as plain text.

Learn how to work it out →