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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)10.2.20.0/25
network10.2.20.0/25
broadcast10.2.20.127
first host10.2.20.1
last host10.2.20.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.2.20.0/25
address00001010.00000010.00010100.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000010.00010100.00000000
broadcast00001010.00000010.00010100.01111111
green = network part, grey = host part
hex0x0a021400
decimal167908352
reverse dns0.20.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:1400

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.2.20.0/3110.2.20.0 – 10.2.20.110.2.20.1
210.2.20.2/3110.2.20.2 – 10.2.20.310.2.20.3
310.2.20.4/3110.2.20.4 – 10.2.20.510.2.20.5
410.2.20.6/3110.2.20.6 – 10.2.20.710.2.20.7
510.2.20.8/3110.2.20.8 – 10.2.20.910.2.20.9
610.2.20.10/3110.2.20.10 – 10.2.20.1110.2.20.11
710.2.20.12/3110.2.20.12 – 10.2.20.1310.2.20.13
810.2.20.14/3110.2.20.14 – 10.2.20.1510.2.20.15
910.2.20.16/3110.2.20.16 – 10.2.20.1710.2.20.17
1010.2.20.18/3110.2.20.18 – 10.2.20.1910.2.20.19
1110.2.20.20/3110.2.20.20 – 10.2.20.2110.2.20.21
1210.2.20.22/3110.2.20.22 – 10.2.20.2310.2.20.23
1310.2.20.24/3110.2.20.24 – 10.2.20.2510.2.20.25
1410.2.20.26/3110.2.20.26 – 10.2.20.2710.2.20.27
1510.2.20.28/3110.2.20.28 – 10.2.20.2910.2.20.29
1610.2.20.30/3110.2.20.30 – 10.2.20.3110.2.20.31
1710.2.20.32/3110.2.20.32 – 10.2.20.3310.2.20.33
1810.2.20.34/3110.2.20.34 – 10.2.20.3510.2.20.35
1910.2.20.36/3110.2.20.36 – 10.2.20.3710.2.20.37
2010.2.20.38/3110.2.20.38 – 10.2.20.3910.2.20.39
2110.2.20.40/3110.2.20.40 – 10.2.20.4110.2.20.41
2210.2.20.42/3110.2.20.42 – 10.2.20.4310.2.20.43
2310.2.20.44/3110.2.20.44 – 10.2.20.4510.2.20.45
2410.2.20.46/3110.2.20.46 – 10.2.20.4710.2.20.47
2510.2.20.48/3110.2.20.48 – 10.2.20.4910.2.20.49
2610.2.20.50/3110.2.20.50 – 10.2.20.5110.2.20.51
2710.2.20.52/3110.2.20.52 – 10.2.20.5310.2.20.53
2810.2.20.54/3110.2.20.54 – 10.2.20.5510.2.20.55
2910.2.20.56/3110.2.20.56 – 10.2.20.5710.2.20.57
3010.2.20.58/3110.2.20.58 – 10.2.20.5910.2.20.59
3110.2.20.60/3110.2.20.60 – 10.2.20.6110.2.20.61
3210.2.20.62/3110.2.20.62 – 10.2.20.6310.2.20.63
3310.2.20.64/3110.2.20.64 – 10.2.20.6510.2.20.65
3410.2.20.66/3110.2.20.66 – 10.2.20.6710.2.20.67
3510.2.20.68/3110.2.20.68 – 10.2.20.6910.2.20.69
3610.2.20.70/3110.2.20.70 – 10.2.20.7110.2.20.71
3710.2.20.72/3110.2.20.72 – 10.2.20.7310.2.20.73
3810.2.20.74/3110.2.20.74 – 10.2.20.7510.2.20.75
3910.2.20.76/3110.2.20.76 – 10.2.20.7710.2.20.77
4010.2.20.78/3110.2.20.78 – 10.2.20.7910.2.20.79
4110.2.20.80/3110.2.20.80 – 10.2.20.8110.2.20.81
4210.2.20.82/3110.2.20.82 – 10.2.20.8310.2.20.83
4310.2.20.84/3110.2.20.84 – 10.2.20.8510.2.20.85
4410.2.20.86/3110.2.20.86 – 10.2.20.8710.2.20.87
4510.2.20.88/3110.2.20.88 – 10.2.20.8910.2.20.89
4610.2.20.90/3110.2.20.90 – 10.2.20.9110.2.20.91
4710.2.20.92/3110.2.20.92 – 10.2.20.9310.2.20.93
4810.2.20.94/3110.2.20.94 – 10.2.20.9510.2.20.95
4910.2.20.96/3110.2.20.96 – 10.2.20.9710.2.20.97
5010.2.20.98/3110.2.20.98 – 10.2.20.9910.2.20.99
5110.2.20.100/3110.2.20.100 – 10.2.20.10110.2.20.101
5210.2.20.102/3110.2.20.102 – 10.2.20.10310.2.20.103
5310.2.20.104/3110.2.20.104 – 10.2.20.10510.2.20.105
5410.2.20.106/3110.2.20.106 – 10.2.20.10710.2.20.107
5510.2.20.108/3110.2.20.108 – 10.2.20.10910.2.20.109
5610.2.20.110/3110.2.20.110 – 10.2.20.11110.2.20.111
5710.2.20.112/3110.2.20.112 – 10.2.20.11310.2.20.113
5810.2.20.114/3110.2.20.114 – 10.2.20.11510.2.20.115
5910.2.20.116/3110.2.20.116 – 10.2.20.11710.2.20.117
6010.2.20.118/3110.2.20.118 – 10.2.20.11910.2.20.119
6110.2.20.120/3110.2.20.120 – 10.2.20.12110.2.20.121
6210.2.20.122/3110.2.20.122 – 10.2.20.12310.2.20.123
6310.2.20.124/3110.2.20.124 – 10.2.20.12510.2.20.125
6410.2.20.126/3110.2.20.126 – 10.2.20.12710.2.20.127
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 →