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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)10.0.81.0/24
network10.0.81.0/24
broadcast10.0.81.255
first host10.0.81.1
last host10.0.81.254
subnet mask255.255.255.0
wildcard0.0.0.255
addresses256
usable hosts254
classA
ipcalc 10.0.81.0/24
address00001010.00000000.01010001.00000000
subnet mask11111111.11111111.11111111.00000000
network00001010.00000000.01010001.00000000
broadcast00001010.00000000.01010001.11111111
green = network part, grey = host part
hex0x0a005100
decimal167792896
reverse dns0.81.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:5100

/24 split into /29 · 32 subnets

close ×
#networkhost rangebroadcast
110.0.81.0/2910.0.81.1 – 10.0.81.610.0.81.7
210.0.81.8/2910.0.81.9 – 10.0.81.1410.0.81.15
310.0.81.16/2910.0.81.17 – 10.0.81.2210.0.81.23
410.0.81.24/2910.0.81.25 – 10.0.81.3010.0.81.31
510.0.81.32/2910.0.81.33 – 10.0.81.3810.0.81.39
610.0.81.40/2910.0.81.41 – 10.0.81.4610.0.81.47
710.0.81.48/2910.0.81.49 – 10.0.81.5410.0.81.55
810.0.81.56/2910.0.81.57 – 10.0.81.6210.0.81.63
910.0.81.64/2910.0.81.65 – 10.0.81.7010.0.81.71
1010.0.81.72/2910.0.81.73 – 10.0.81.7810.0.81.79
1110.0.81.80/2910.0.81.81 – 10.0.81.8610.0.81.87
1210.0.81.88/2910.0.81.89 – 10.0.81.9410.0.81.95
1310.0.81.96/2910.0.81.97 – 10.0.81.10210.0.81.103
1410.0.81.104/2910.0.81.105 – 10.0.81.11010.0.81.111
1510.0.81.112/2910.0.81.113 – 10.0.81.11810.0.81.119
1610.0.81.120/2910.0.81.121 – 10.0.81.12610.0.81.127
1710.0.81.128/2910.0.81.129 – 10.0.81.13410.0.81.135
1810.0.81.136/2910.0.81.137 – 10.0.81.14210.0.81.143
1910.0.81.144/2910.0.81.145 – 10.0.81.15010.0.81.151
2010.0.81.152/2910.0.81.153 – 10.0.81.15810.0.81.159
2110.0.81.160/2910.0.81.161 – 10.0.81.16610.0.81.167
2210.0.81.168/2910.0.81.169 – 10.0.81.17410.0.81.175
2310.0.81.176/2910.0.81.177 – 10.0.81.18210.0.81.183
2410.0.81.184/2910.0.81.185 – 10.0.81.19010.0.81.191
2510.0.81.192/2910.0.81.193 – 10.0.81.19810.0.81.199
2610.0.81.200/2910.0.81.201 – 10.0.81.20610.0.81.207
2710.0.81.208/2910.0.81.209 – 10.0.81.21410.0.81.215
2810.0.81.216/2910.0.81.217 – 10.0.81.22210.0.81.223
2910.0.81.224/2910.0.81.225 – 10.0.81.23010.0.81.231
3010.0.81.232/2910.0.81.233 – 10.0.81.23810.0.81.239
3110.0.81.240/2910.0.81.241 – 10.0.81.24610.0.81.247
3210.0.81.248/2910.0.81.249 – 10.0.81.25410.0.81.255
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /24
/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-
/24255.255.255.02562541
/25255.255.255.1281281262 split →
/26255.255.255.19264624 split →
/27255.255.255.22432308 split →
/28255.255.255.240161416 split →
/29255.255.255.2488632 split →
/30255.255.255.2524264 split →
/31255.255.255.25422128 split →
/32255.255.255.25511256 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 →