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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)172.16.12.0/24
network172.16.12.0/24
broadcast172.16.12.255
first host172.16.12.1
last host172.16.12.254
subnet mask255.255.255.0
wildcard0.0.0.255
addresses256
usable hosts254
classB
ipcalc 172.16.12.0/24
address10101100.00010000.00001100.00000000
subnet mask11111111.11111111.11111111.00000000
network10101100.00010000.00001100.00000000
broadcast10101100.00010000.00001100.11111111
green = network part, grey = host part
hex0xac100c00
decimal2886732800
reverse dns0.12.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:c00

/24 split into /28 · 16 subnets

close ×
#networkhost rangebroadcast
1172.16.12.0/28172.16.12.1 – 172.16.12.14172.16.12.15
2172.16.12.16/28172.16.12.17 – 172.16.12.30172.16.12.31
3172.16.12.32/28172.16.12.33 – 172.16.12.46172.16.12.47
4172.16.12.48/28172.16.12.49 – 172.16.12.62172.16.12.63
5172.16.12.64/28172.16.12.65 – 172.16.12.78172.16.12.79
6172.16.12.80/28172.16.12.81 – 172.16.12.94172.16.12.95
7172.16.12.96/28172.16.12.97 – 172.16.12.110172.16.12.111
8172.16.12.112/28172.16.12.113 – 172.16.12.126172.16.12.127
9172.16.12.128/28172.16.12.129 – 172.16.12.142172.16.12.143
10172.16.12.144/28172.16.12.145 – 172.16.12.158172.16.12.159
11172.16.12.160/28172.16.12.161 – 172.16.12.174172.16.12.175
12172.16.12.176/28172.16.12.177 – 172.16.12.190172.16.12.191
13172.16.12.192/28172.16.12.193 – 172.16.12.206172.16.12.207
14172.16.12.208/28172.16.12.209 – 172.16.12.222172.16.12.223
15172.16.12.224/28172.16.12.225 – 172.16.12.238172.16.12.239
16172.16.12.240/28172.16.12.241 – 172.16.12.254172.16.12.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /24
/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-
/24255.255.255.02562541
/25255.255.255.1281281262 split →
/26255.255.255.19264624 split →
/27255.255.255.22432308 split →
/28255.255.255.240161416 split →
/29255.255.255.2488632 split →
/30255.255.255.2524264 split →
/31255.255.255.25422128 split →
/32255.255.255.25511256 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 →