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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)10.3.237.0/25
network10.3.237.0/25
broadcast10.3.237.127
first host10.3.237.1
last host10.3.237.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.3.237.0/25
address00001010.00000011.11101101.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000011.11101101.00000000
broadcast00001010.00000011.11101101.01111111
green = network part, grey = host part
hex0x0a03ed00
decimal168029440
reverse dns0.237.3.10.in-addr.arpa
ipv4-mapped::ffff:a03:ed00

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
110.3.237.0/3010.3.237.1 – 10.3.237.210.3.237.3
210.3.237.4/3010.3.237.5 – 10.3.237.610.3.237.7
310.3.237.8/3010.3.237.9 – 10.3.237.1010.3.237.11
410.3.237.12/3010.3.237.13 – 10.3.237.1410.3.237.15
510.3.237.16/3010.3.237.17 – 10.3.237.1810.3.237.19
610.3.237.20/3010.3.237.21 – 10.3.237.2210.3.237.23
710.3.237.24/3010.3.237.25 – 10.3.237.2610.3.237.27
810.3.237.28/3010.3.237.29 – 10.3.237.3010.3.237.31
910.3.237.32/3010.3.237.33 – 10.3.237.3410.3.237.35
1010.3.237.36/3010.3.237.37 – 10.3.237.3810.3.237.39
1110.3.237.40/3010.3.237.41 – 10.3.237.4210.3.237.43
1210.3.237.44/3010.3.237.45 – 10.3.237.4610.3.237.47
1310.3.237.48/3010.3.237.49 – 10.3.237.5010.3.237.51
1410.3.237.52/3010.3.237.53 – 10.3.237.5410.3.237.55
1510.3.237.56/3010.3.237.57 – 10.3.237.5810.3.237.59
1610.3.237.60/3010.3.237.61 – 10.3.237.6210.3.237.63
1710.3.237.64/3010.3.237.65 – 10.3.237.6610.3.237.67
1810.3.237.68/3010.3.237.69 – 10.3.237.7010.3.237.71
1910.3.237.72/3010.3.237.73 – 10.3.237.7410.3.237.75
2010.3.237.76/3010.3.237.77 – 10.3.237.7810.3.237.79
2110.3.237.80/3010.3.237.81 – 10.3.237.8210.3.237.83
2210.3.237.84/3010.3.237.85 – 10.3.237.8610.3.237.87
2310.3.237.88/3010.3.237.89 – 10.3.237.9010.3.237.91
2410.3.237.92/3010.3.237.93 – 10.3.237.9410.3.237.95
2510.3.237.96/3010.3.237.97 – 10.3.237.9810.3.237.99
2610.3.237.100/3010.3.237.101 – 10.3.237.10210.3.237.103
2710.3.237.104/3010.3.237.105 – 10.3.237.10610.3.237.107
2810.3.237.108/3010.3.237.109 – 10.3.237.11010.3.237.111
2910.3.237.112/3010.3.237.113 – 10.3.237.11410.3.237.115
3010.3.237.116/3010.3.237.117 – 10.3.237.11810.3.237.119
3110.3.237.120/3010.3.237.121 – 10.3.237.12210.3.237.123
3210.3.237.124/3010.3.237.125 – 10.3.237.12610.3.237.127
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 →