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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)10.2.91.0/25
network10.2.91.0/25
broadcast10.2.91.127
first host10.2.91.1
last host10.2.91.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.2.91.0/25
address00001010.00000010.01011011.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000010.01011011.00000000
broadcast00001010.00000010.01011011.01111111
green = network part, grey = host part
hex0x0a025b00
decimal167926528
reverse dns0.91.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:5b00

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.2.91.0/3110.2.91.0 – 10.2.91.110.2.91.1
210.2.91.2/3110.2.91.2 – 10.2.91.310.2.91.3
310.2.91.4/3110.2.91.4 – 10.2.91.510.2.91.5
410.2.91.6/3110.2.91.6 – 10.2.91.710.2.91.7
510.2.91.8/3110.2.91.8 – 10.2.91.910.2.91.9
610.2.91.10/3110.2.91.10 – 10.2.91.1110.2.91.11
710.2.91.12/3110.2.91.12 – 10.2.91.1310.2.91.13
810.2.91.14/3110.2.91.14 – 10.2.91.1510.2.91.15
910.2.91.16/3110.2.91.16 – 10.2.91.1710.2.91.17
1010.2.91.18/3110.2.91.18 – 10.2.91.1910.2.91.19
1110.2.91.20/3110.2.91.20 – 10.2.91.2110.2.91.21
1210.2.91.22/3110.2.91.22 – 10.2.91.2310.2.91.23
1310.2.91.24/3110.2.91.24 – 10.2.91.2510.2.91.25
1410.2.91.26/3110.2.91.26 – 10.2.91.2710.2.91.27
1510.2.91.28/3110.2.91.28 – 10.2.91.2910.2.91.29
1610.2.91.30/3110.2.91.30 – 10.2.91.3110.2.91.31
1710.2.91.32/3110.2.91.32 – 10.2.91.3310.2.91.33
1810.2.91.34/3110.2.91.34 – 10.2.91.3510.2.91.35
1910.2.91.36/3110.2.91.36 – 10.2.91.3710.2.91.37
2010.2.91.38/3110.2.91.38 – 10.2.91.3910.2.91.39
2110.2.91.40/3110.2.91.40 – 10.2.91.4110.2.91.41
2210.2.91.42/3110.2.91.42 – 10.2.91.4310.2.91.43
2310.2.91.44/3110.2.91.44 – 10.2.91.4510.2.91.45
2410.2.91.46/3110.2.91.46 – 10.2.91.4710.2.91.47
2510.2.91.48/3110.2.91.48 – 10.2.91.4910.2.91.49
2610.2.91.50/3110.2.91.50 – 10.2.91.5110.2.91.51
2710.2.91.52/3110.2.91.52 – 10.2.91.5310.2.91.53
2810.2.91.54/3110.2.91.54 – 10.2.91.5510.2.91.55
2910.2.91.56/3110.2.91.56 – 10.2.91.5710.2.91.57
3010.2.91.58/3110.2.91.58 – 10.2.91.5910.2.91.59
3110.2.91.60/3110.2.91.60 – 10.2.91.6110.2.91.61
3210.2.91.62/3110.2.91.62 – 10.2.91.6310.2.91.63
3310.2.91.64/3110.2.91.64 – 10.2.91.6510.2.91.65
3410.2.91.66/3110.2.91.66 – 10.2.91.6710.2.91.67
3510.2.91.68/3110.2.91.68 – 10.2.91.6910.2.91.69
3610.2.91.70/3110.2.91.70 – 10.2.91.7110.2.91.71
3710.2.91.72/3110.2.91.72 – 10.2.91.7310.2.91.73
3810.2.91.74/3110.2.91.74 – 10.2.91.7510.2.91.75
3910.2.91.76/3110.2.91.76 – 10.2.91.7710.2.91.77
4010.2.91.78/3110.2.91.78 – 10.2.91.7910.2.91.79
4110.2.91.80/3110.2.91.80 – 10.2.91.8110.2.91.81
4210.2.91.82/3110.2.91.82 – 10.2.91.8310.2.91.83
4310.2.91.84/3110.2.91.84 – 10.2.91.8510.2.91.85
4410.2.91.86/3110.2.91.86 – 10.2.91.8710.2.91.87
4510.2.91.88/3110.2.91.88 – 10.2.91.8910.2.91.89
4610.2.91.90/3110.2.91.90 – 10.2.91.9110.2.91.91
4710.2.91.92/3110.2.91.92 – 10.2.91.9310.2.91.93
4810.2.91.94/3110.2.91.94 – 10.2.91.9510.2.91.95
4910.2.91.96/3110.2.91.96 – 10.2.91.9710.2.91.97
5010.2.91.98/3110.2.91.98 – 10.2.91.9910.2.91.99
5110.2.91.100/3110.2.91.100 – 10.2.91.10110.2.91.101
5210.2.91.102/3110.2.91.102 – 10.2.91.10310.2.91.103
5310.2.91.104/3110.2.91.104 – 10.2.91.10510.2.91.105
5410.2.91.106/3110.2.91.106 – 10.2.91.10710.2.91.107
5510.2.91.108/3110.2.91.108 – 10.2.91.10910.2.91.109
5610.2.91.110/3110.2.91.110 – 10.2.91.11110.2.91.111
5710.2.91.112/3110.2.91.112 – 10.2.91.11310.2.91.113
5810.2.91.114/3110.2.91.114 – 10.2.91.11510.2.91.115
5910.2.91.116/3110.2.91.116 – 10.2.91.11710.2.91.117
6010.2.91.118/3110.2.91.118 – 10.2.91.11910.2.91.119
6110.2.91.120/3110.2.91.120 – 10.2.91.12110.2.91.121
6210.2.91.122/3110.2.91.122 – 10.2.91.12310.2.91.123
6310.2.91.124/3110.2.91.124 – 10.2.91.12510.2.91.125
6410.2.91.126/3110.2.91.126 – 10.2.91.12710.2.91.127
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 →