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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)10.3.18.0/25
network10.3.18.0/25
broadcast10.3.18.127
first host10.3.18.1
last host10.3.18.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.3.18.0/25
address00001010.00000011.00010010.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000011.00010010.00000000
broadcast00001010.00000011.00010010.01111111
green = network part, grey = host part
hex0x0a031200
decimal167973376
reverse dns0.18.3.10.in-addr.arpa
ipv4-mapped::ffff:a03:1200

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.3.18.0/3110.3.18.0 – 10.3.18.110.3.18.1
210.3.18.2/3110.3.18.2 – 10.3.18.310.3.18.3
310.3.18.4/3110.3.18.4 – 10.3.18.510.3.18.5
410.3.18.6/3110.3.18.6 – 10.3.18.710.3.18.7
510.3.18.8/3110.3.18.8 – 10.3.18.910.3.18.9
610.3.18.10/3110.3.18.10 – 10.3.18.1110.3.18.11
710.3.18.12/3110.3.18.12 – 10.3.18.1310.3.18.13
810.3.18.14/3110.3.18.14 – 10.3.18.1510.3.18.15
910.3.18.16/3110.3.18.16 – 10.3.18.1710.3.18.17
1010.3.18.18/3110.3.18.18 – 10.3.18.1910.3.18.19
1110.3.18.20/3110.3.18.20 – 10.3.18.2110.3.18.21
1210.3.18.22/3110.3.18.22 – 10.3.18.2310.3.18.23
1310.3.18.24/3110.3.18.24 – 10.3.18.2510.3.18.25
1410.3.18.26/3110.3.18.26 – 10.3.18.2710.3.18.27
1510.3.18.28/3110.3.18.28 – 10.3.18.2910.3.18.29
1610.3.18.30/3110.3.18.30 – 10.3.18.3110.3.18.31
1710.3.18.32/3110.3.18.32 – 10.3.18.3310.3.18.33
1810.3.18.34/3110.3.18.34 – 10.3.18.3510.3.18.35
1910.3.18.36/3110.3.18.36 – 10.3.18.3710.3.18.37
2010.3.18.38/3110.3.18.38 – 10.3.18.3910.3.18.39
2110.3.18.40/3110.3.18.40 – 10.3.18.4110.3.18.41
2210.3.18.42/3110.3.18.42 – 10.3.18.4310.3.18.43
2310.3.18.44/3110.3.18.44 – 10.3.18.4510.3.18.45
2410.3.18.46/3110.3.18.46 – 10.3.18.4710.3.18.47
2510.3.18.48/3110.3.18.48 – 10.3.18.4910.3.18.49
2610.3.18.50/3110.3.18.50 – 10.3.18.5110.3.18.51
2710.3.18.52/3110.3.18.52 – 10.3.18.5310.3.18.53
2810.3.18.54/3110.3.18.54 – 10.3.18.5510.3.18.55
2910.3.18.56/3110.3.18.56 – 10.3.18.5710.3.18.57
3010.3.18.58/3110.3.18.58 – 10.3.18.5910.3.18.59
3110.3.18.60/3110.3.18.60 – 10.3.18.6110.3.18.61
3210.3.18.62/3110.3.18.62 – 10.3.18.6310.3.18.63
3310.3.18.64/3110.3.18.64 – 10.3.18.6510.3.18.65
3410.3.18.66/3110.3.18.66 – 10.3.18.6710.3.18.67
3510.3.18.68/3110.3.18.68 – 10.3.18.6910.3.18.69
3610.3.18.70/3110.3.18.70 – 10.3.18.7110.3.18.71
3710.3.18.72/3110.3.18.72 – 10.3.18.7310.3.18.73
3810.3.18.74/3110.3.18.74 – 10.3.18.7510.3.18.75
3910.3.18.76/3110.3.18.76 – 10.3.18.7710.3.18.77
4010.3.18.78/3110.3.18.78 – 10.3.18.7910.3.18.79
4110.3.18.80/3110.3.18.80 – 10.3.18.8110.3.18.81
4210.3.18.82/3110.3.18.82 – 10.3.18.8310.3.18.83
4310.3.18.84/3110.3.18.84 – 10.3.18.8510.3.18.85
4410.3.18.86/3110.3.18.86 – 10.3.18.8710.3.18.87
4510.3.18.88/3110.3.18.88 – 10.3.18.8910.3.18.89
4610.3.18.90/3110.3.18.90 – 10.3.18.9110.3.18.91
4710.3.18.92/3110.3.18.92 – 10.3.18.9310.3.18.93
4810.3.18.94/3110.3.18.94 – 10.3.18.9510.3.18.95
4910.3.18.96/3110.3.18.96 – 10.3.18.9710.3.18.97
5010.3.18.98/3110.3.18.98 – 10.3.18.9910.3.18.99
5110.3.18.100/3110.3.18.100 – 10.3.18.10110.3.18.101
5210.3.18.102/3110.3.18.102 – 10.3.18.10310.3.18.103
5310.3.18.104/3110.3.18.104 – 10.3.18.10510.3.18.105
5410.3.18.106/3110.3.18.106 – 10.3.18.10710.3.18.107
5510.3.18.108/3110.3.18.108 – 10.3.18.10910.3.18.109
5610.3.18.110/3110.3.18.110 – 10.3.18.11110.3.18.111
5710.3.18.112/3110.3.18.112 – 10.3.18.11310.3.18.113
5810.3.18.114/3110.3.18.114 – 10.3.18.11510.3.18.115
5910.3.18.116/3110.3.18.116 – 10.3.18.11710.3.18.117
6010.3.18.118/3110.3.18.118 – 10.3.18.11910.3.18.119
6110.3.18.120/3110.3.18.120 – 10.3.18.12110.3.18.121
6210.3.18.122/3110.3.18.122 – 10.3.18.12310.3.18.123
6310.3.18.124/3110.3.18.124 – 10.3.18.12510.3.18.125
6410.3.18.126/3110.3.18.126 – 10.3.18.12710.3.18.127
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 →