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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)10.0.20.128/26
network10.0.20.128/26
broadcast10.0.20.191
first host10.0.20.129
last host10.0.20.190
subnet mask255.255.255.192
wildcard0.0.0.63
addresses64
usable hosts62
classA
ipcalc 10.0.20.128/26
address00001010.00000000.00010100.10000000
subnet mask11111111.11111111.11111111.11000000
network00001010.00000000.00010100.10000000
broadcast00001010.00000000.00010100.10111111
green = network part, grey = host part
hex0x0a001480
decimal167777408
reverse dns128.20.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:1480

/26 split into /31 · 32 subnets

close ×
#networkhost rangebroadcast
110.0.20.128/3110.0.20.128 – 10.0.20.12910.0.20.129
210.0.20.130/3110.0.20.130 – 10.0.20.13110.0.20.131
310.0.20.132/3110.0.20.132 – 10.0.20.13310.0.20.133
410.0.20.134/3110.0.20.134 – 10.0.20.13510.0.20.135
510.0.20.136/3110.0.20.136 – 10.0.20.13710.0.20.137
610.0.20.138/3110.0.20.138 – 10.0.20.13910.0.20.139
710.0.20.140/3110.0.20.140 – 10.0.20.14110.0.20.141
810.0.20.142/3110.0.20.142 – 10.0.20.14310.0.20.143
910.0.20.144/3110.0.20.144 – 10.0.20.14510.0.20.145
1010.0.20.146/3110.0.20.146 – 10.0.20.14710.0.20.147
1110.0.20.148/3110.0.20.148 – 10.0.20.14910.0.20.149
1210.0.20.150/3110.0.20.150 – 10.0.20.15110.0.20.151
1310.0.20.152/3110.0.20.152 – 10.0.20.15310.0.20.153
1410.0.20.154/3110.0.20.154 – 10.0.20.15510.0.20.155
1510.0.20.156/3110.0.20.156 – 10.0.20.15710.0.20.157
1610.0.20.158/3110.0.20.158 – 10.0.20.15910.0.20.159
1710.0.20.160/3110.0.20.160 – 10.0.20.16110.0.20.161
1810.0.20.162/3110.0.20.162 – 10.0.20.16310.0.20.163
1910.0.20.164/3110.0.20.164 – 10.0.20.16510.0.20.165
2010.0.20.166/3110.0.20.166 – 10.0.20.16710.0.20.167
2110.0.20.168/3110.0.20.168 – 10.0.20.16910.0.20.169
2210.0.20.170/3110.0.20.170 – 10.0.20.17110.0.20.171
2310.0.20.172/3110.0.20.172 – 10.0.20.17310.0.20.173
2410.0.20.174/3110.0.20.174 – 10.0.20.17510.0.20.175
2510.0.20.176/3110.0.20.176 – 10.0.20.17710.0.20.177
2610.0.20.178/3110.0.20.178 – 10.0.20.17910.0.20.179
2710.0.20.180/3110.0.20.180 – 10.0.20.18110.0.20.181
2810.0.20.182/3110.0.20.182 – 10.0.20.18310.0.20.183
2910.0.20.184/3110.0.20.184 – 10.0.20.18510.0.20.185
3010.0.20.186/3110.0.20.186 – 10.0.20.18710.0.20.187
3110.0.20.188/3110.0.20.188 – 10.0.20.18910.0.20.189
3210.0.20.190/3110.0.20.190 – 10.0.20.19110.0.20.191
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /26
/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-
/25255.255.255.128128126-
/26255.255.255.19264621
/27255.255.255.22432302 split →
/28255.255.255.24016144 split →
/29255.255.255.248868 split →
/30255.255.255.2524216 split →
/31255.255.255.2542232 split →
/32255.255.255.2551164 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 →