ip
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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)10.2.57.0/25
network10.2.57.0/25
broadcast10.2.57.127
first host10.2.57.1
last host10.2.57.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.2.57.0/25
address00001010.00000010.00111001.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000010.00111001.00000000
broadcast00001010.00000010.00111001.01111111
green = network part, grey = host part
hex0x0a023900
decimal167917824
reverse dns0.57.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:3900

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
110.2.57.0/3010.2.57.1 – 10.2.57.210.2.57.3
210.2.57.4/3010.2.57.5 – 10.2.57.610.2.57.7
310.2.57.8/3010.2.57.9 – 10.2.57.1010.2.57.11
410.2.57.12/3010.2.57.13 – 10.2.57.1410.2.57.15
510.2.57.16/3010.2.57.17 – 10.2.57.1810.2.57.19
610.2.57.20/3010.2.57.21 – 10.2.57.2210.2.57.23
710.2.57.24/3010.2.57.25 – 10.2.57.2610.2.57.27
810.2.57.28/3010.2.57.29 – 10.2.57.3010.2.57.31
910.2.57.32/3010.2.57.33 – 10.2.57.3410.2.57.35
1010.2.57.36/3010.2.57.37 – 10.2.57.3810.2.57.39
1110.2.57.40/3010.2.57.41 – 10.2.57.4210.2.57.43
1210.2.57.44/3010.2.57.45 – 10.2.57.4610.2.57.47
1310.2.57.48/3010.2.57.49 – 10.2.57.5010.2.57.51
1410.2.57.52/3010.2.57.53 – 10.2.57.5410.2.57.55
1510.2.57.56/3010.2.57.57 – 10.2.57.5810.2.57.59
1610.2.57.60/3010.2.57.61 – 10.2.57.6210.2.57.63
1710.2.57.64/3010.2.57.65 – 10.2.57.6610.2.57.67
1810.2.57.68/3010.2.57.69 – 10.2.57.7010.2.57.71
1910.2.57.72/3010.2.57.73 – 10.2.57.7410.2.57.75
2010.2.57.76/3010.2.57.77 – 10.2.57.7810.2.57.79
2110.2.57.80/3010.2.57.81 – 10.2.57.8210.2.57.83
2210.2.57.84/3010.2.57.85 – 10.2.57.8610.2.57.87
2310.2.57.88/3010.2.57.89 – 10.2.57.9010.2.57.91
2410.2.57.92/3010.2.57.93 – 10.2.57.9410.2.57.95
2510.2.57.96/3010.2.57.97 – 10.2.57.9810.2.57.99
2610.2.57.100/3010.2.57.101 – 10.2.57.10210.2.57.103
2710.2.57.104/3010.2.57.105 – 10.2.57.10610.2.57.107
2810.2.57.108/3010.2.57.109 – 10.2.57.11010.2.57.111
2910.2.57.112/3010.2.57.113 – 10.2.57.11410.2.57.115
3010.2.57.116/3010.2.57.117 – 10.2.57.11810.2.57.119
3110.2.57.120/3010.2.57.121 – 10.2.57.12210.2.57.123
3210.2.57.124/3010.2.57.125 – 10.2.57.12610.2.57.127
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 →