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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)10.65.21.128/26
network10.65.21.128/26
broadcast10.65.21.191
first host10.65.21.129
last host10.65.21.190
subnet mask255.255.255.192
wildcard0.0.0.63
addresses64
usable hosts62
classA
ipcalc 10.65.21.128/26
address00001010.01000001.00010101.10000000
subnet mask11111111.11111111.11111111.11000000
network00001010.01000001.00010101.10000000
broadcast00001010.01000001.00010101.10111111
green = network part, grey = host part
hex0x0a411580
decimal172037504
reverse dns128.21.65.10.in-addr.arpa
ipv4-mapped::ffff:a41:1580

/26 split into /31 · 32 subnets

close ×
#networkhost rangebroadcast
110.65.21.128/3110.65.21.128 – 10.65.21.12910.65.21.129
210.65.21.130/3110.65.21.130 – 10.65.21.13110.65.21.131
310.65.21.132/3110.65.21.132 – 10.65.21.13310.65.21.133
410.65.21.134/3110.65.21.134 – 10.65.21.13510.65.21.135
510.65.21.136/3110.65.21.136 – 10.65.21.13710.65.21.137
610.65.21.138/3110.65.21.138 – 10.65.21.13910.65.21.139
710.65.21.140/3110.65.21.140 – 10.65.21.14110.65.21.141
810.65.21.142/3110.65.21.142 – 10.65.21.14310.65.21.143
910.65.21.144/3110.65.21.144 – 10.65.21.14510.65.21.145
1010.65.21.146/3110.65.21.146 – 10.65.21.14710.65.21.147
1110.65.21.148/3110.65.21.148 – 10.65.21.14910.65.21.149
1210.65.21.150/3110.65.21.150 – 10.65.21.15110.65.21.151
1310.65.21.152/3110.65.21.152 – 10.65.21.15310.65.21.153
1410.65.21.154/3110.65.21.154 – 10.65.21.15510.65.21.155
1510.65.21.156/3110.65.21.156 – 10.65.21.15710.65.21.157
1610.65.21.158/3110.65.21.158 – 10.65.21.15910.65.21.159
1710.65.21.160/3110.65.21.160 – 10.65.21.16110.65.21.161
1810.65.21.162/3110.65.21.162 – 10.65.21.16310.65.21.163
1910.65.21.164/3110.65.21.164 – 10.65.21.16510.65.21.165
2010.65.21.166/3110.65.21.166 – 10.65.21.16710.65.21.167
2110.65.21.168/3110.65.21.168 – 10.65.21.16910.65.21.169
2210.65.21.170/3110.65.21.170 – 10.65.21.17110.65.21.171
2310.65.21.172/3110.65.21.172 – 10.65.21.17310.65.21.173
2410.65.21.174/3110.65.21.174 – 10.65.21.17510.65.21.175
2510.65.21.176/3110.65.21.176 – 10.65.21.17710.65.21.177
2610.65.21.178/3110.65.21.178 – 10.65.21.17910.65.21.179
2710.65.21.180/3110.65.21.180 – 10.65.21.18110.65.21.181
2810.65.21.182/3110.65.21.182 – 10.65.21.18310.65.21.183
2910.65.21.184/3110.65.21.184 – 10.65.21.18510.65.21.185
3010.65.21.186/3110.65.21.186 – 10.65.21.18710.65.21.187
3110.65.21.188/3110.65.21.188 – 10.65.21.18910.65.21.189
3210.65.21.190/3110.65.21.190 – 10.65.21.19110.65.21.191
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 →