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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
private IP (RFC 1918)10.2.31.0/25
network10.2.31.0/25
broadcast10.2.31.127
first host10.2.31.1
last host10.2.31.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.2.31.0/25
address00001010.00000010.00011111.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000010.00011111.00000000
broadcast00001010.00000010.00011111.01111111
green = network part, grey = host part
hex0x0a021f00
decimal167911168
reverse dns0.31.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:1f00

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.2.31.0/3110.2.31.0 – 10.2.31.110.2.31.1
210.2.31.2/3110.2.31.2 – 10.2.31.310.2.31.3
310.2.31.4/3110.2.31.4 – 10.2.31.510.2.31.5
410.2.31.6/3110.2.31.6 – 10.2.31.710.2.31.7
510.2.31.8/3110.2.31.8 – 10.2.31.910.2.31.9
610.2.31.10/3110.2.31.10 – 10.2.31.1110.2.31.11
710.2.31.12/3110.2.31.12 – 10.2.31.1310.2.31.13
810.2.31.14/3110.2.31.14 – 10.2.31.1510.2.31.15
910.2.31.16/3110.2.31.16 – 10.2.31.1710.2.31.17
1010.2.31.18/3110.2.31.18 – 10.2.31.1910.2.31.19
1110.2.31.20/3110.2.31.20 – 10.2.31.2110.2.31.21
1210.2.31.22/3110.2.31.22 – 10.2.31.2310.2.31.23
1310.2.31.24/3110.2.31.24 – 10.2.31.2510.2.31.25
1410.2.31.26/3110.2.31.26 – 10.2.31.2710.2.31.27
1510.2.31.28/3110.2.31.28 – 10.2.31.2910.2.31.29
1610.2.31.30/3110.2.31.30 – 10.2.31.3110.2.31.31
1710.2.31.32/3110.2.31.32 – 10.2.31.3310.2.31.33
1810.2.31.34/3110.2.31.34 – 10.2.31.3510.2.31.35
1910.2.31.36/3110.2.31.36 – 10.2.31.3710.2.31.37
2010.2.31.38/3110.2.31.38 – 10.2.31.3910.2.31.39
2110.2.31.40/3110.2.31.40 – 10.2.31.4110.2.31.41
2210.2.31.42/3110.2.31.42 – 10.2.31.4310.2.31.43
2310.2.31.44/3110.2.31.44 – 10.2.31.4510.2.31.45
2410.2.31.46/3110.2.31.46 – 10.2.31.4710.2.31.47
2510.2.31.48/3110.2.31.48 – 10.2.31.4910.2.31.49
2610.2.31.50/3110.2.31.50 – 10.2.31.5110.2.31.51
2710.2.31.52/3110.2.31.52 – 10.2.31.5310.2.31.53
2810.2.31.54/3110.2.31.54 – 10.2.31.5510.2.31.55
2910.2.31.56/3110.2.31.56 – 10.2.31.5710.2.31.57
3010.2.31.58/3110.2.31.58 – 10.2.31.5910.2.31.59
3110.2.31.60/3110.2.31.60 – 10.2.31.6110.2.31.61
3210.2.31.62/3110.2.31.62 – 10.2.31.6310.2.31.63
3310.2.31.64/3110.2.31.64 – 10.2.31.6510.2.31.65
3410.2.31.66/3110.2.31.66 – 10.2.31.6710.2.31.67
3510.2.31.68/3110.2.31.68 – 10.2.31.6910.2.31.69
3610.2.31.70/3110.2.31.70 – 10.2.31.7110.2.31.71
3710.2.31.72/3110.2.31.72 – 10.2.31.7310.2.31.73
3810.2.31.74/3110.2.31.74 – 10.2.31.7510.2.31.75
3910.2.31.76/3110.2.31.76 – 10.2.31.7710.2.31.77
4010.2.31.78/3110.2.31.78 – 10.2.31.7910.2.31.79
4110.2.31.80/3110.2.31.80 – 10.2.31.8110.2.31.81
4210.2.31.82/3110.2.31.82 – 10.2.31.8310.2.31.83
4310.2.31.84/3110.2.31.84 – 10.2.31.8510.2.31.85
4410.2.31.86/3110.2.31.86 – 10.2.31.8710.2.31.87
4510.2.31.88/3110.2.31.88 – 10.2.31.8910.2.31.89
4610.2.31.90/3110.2.31.90 – 10.2.31.9110.2.31.91
4710.2.31.92/3110.2.31.92 – 10.2.31.9310.2.31.93
4810.2.31.94/3110.2.31.94 – 10.2.31.9510.2.31.95
4910.2.31.96/3110.2.31.96 – 10.2.31.9710.2.31.97
5010.2.31.98/3110.2.31.98 – 10.2.31.9910.2.31.99
5110.2.31.100/3110.2.31.100 – 10.2.31.10110.2.31.101
5210.2.31.102/3110.2.31.102 – 10.2.31.10310.2.31.103
5310.2.31.104/3110.2.31.104 – 10.2.31.10510.2.31.105
5410.2.31.106/3110.2.31.106 – 10.2.31.10710.2.31.107
5510.2.31.108/3110.2.31.108 – 10.2.31.10910.2.31.109
5610.2.31.110/3110.2.31.110 – 10.2.31.11110.2.31.111
5710.2.31.112/3110.2.31.112 – 10.2.31.11310.2.31.113
5810.2.31.114/3110.2.31.114 – 10.2.31.11510.2.31.115
5910.2.31.116/3110.2.31.116 – 10.2.31.11710.2.31.117
6010.2.31.118/3110.2.31.118 – 10.2.31.11910.2.31.119
6110.2.31.120/3110.2.31.120 – 10.2.31.12110.2.31.121
6210.2.31.122/3110.2.31.122 – 10.2.31.12310.2.31.123
6310.2.31.124/3110.2.31.124 – 10.2.31.12510.2.31.125
6410.2.31.126/3110.2.31.126 – 10.2.31.12710.2.31.127
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 →