ip
ipku.in

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)10.166.64.0/25
network10.166.64.0/25
broadcast10.166.64.127
first host10.166.64.1
last host10.166.64.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.166.64.0/25
address00001010.10100110.01000000.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.10100110.01000000.00000000
broadcast00001010.10100110.01000000.01111111
green = network part, grey = host part
hex0x0aa64000
decimal178667520
reverse dns0.64.166.10.in-addr.arpa
ipv4-mapped::ffff:aa6:4000

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
110.166.64.0/3010.166.64.1 – 10.166.64.210.166.64.3
210.166.64.4/3010.166.64.5 – 10.166.64.610.166.64.7
310.166.64.8/3010.166.64.9 – 10.166.64.1010.166.64.11
410.166.64.12/3010.166.64.13 – 10.166.64.1410.166.64.15
510.166.64.16/3010.166.64.17 – 10.166.64.1810.166.64.19
610.166.64.20/3010.166.64.21 – 10.166.64.2210.166.64.23
710.166.64.24/3010.166.64.25 – 10.166.64.2610.166.64.27
810.166.64.28/3010.166.64.29 – 10.166.64.3010.166.64.31
910.166.64.32/3010.166.64.33 – 10.166.64.3410.166.64.35
1010.166.64.36/3010.166.64.37 – 10.166.64.3810.166.64.39
1110.166.64.40/3010.166.64.41 – 10.166.64.4210.166.64.43
1210.166.64.44/3010.166.64.45 – 10.166.64.4610.166.64.47
1310.166.64.48/3010.166.64.49 – 10.166.64.5010.166.64.51
1410.166.64.52/3010.166.64.53 – 10.166.64.5410.166.64.55
1510.166.64.56/3010.166.64.57 – 10.166.64.5810.166.64.59
1610.166.64.60/3010.166.64.61 – 10.166.64.6210.166.64.63
1710.166.64.64/3010.166.64.65 – 10.166.64.6610.166.64.67
1810.166.64.68/3010.166.64.69 – 10.166.64.7010.166.64.71
1910.166.64.72/3010.166.64.73 – 10.166.64.7410.166.64.75
2010.166.64.76/3010.166.64.77 – 10.166.64.7810.166.64.79
2110.166.64.80/3010.166.64.81 – 10.166.64.8210.166.64.83
2210.166.64.84/3010.166.64.85 – 10.166.64.8610.166.64.87
2310.166.64.88/3010.166.64.89 – 10.166.64.9010.166.64.91
2410.166.64.92/3010.166.64.93 – 10.166.64.9410.166.64.95
2510.166.64.96/3010.166.64.97 – 10.166.64.9810.166.64.99
2610.166.64.100/3010.166.64.101 – 10.166.64.10210.166.64.103
2710.166.64.104/3010.166.64.105 – 10.166.64.10610.166.64.107
2810.166.64.108/3010.166.64.109 – 10.166.64.11010.166.64.111
2910.166.64.112/3010.166.64.113 – 10.166.64.11410.166.64.115
3010.166.64.116/3010.166.64.117 – 10.166.64.11810.166.64.119
3110.166.64.120/3010.166.64.121 – 10.166.64.12210.166.64.123
3210.166.64.124/3010.166.64.125 – 10.166.64.12610.166.64.127
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 →