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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)10.2.66.0/23
network10.2.66.0/23
broadcast10.2.67.255
first host10.2.66.1
last host10.2.67.254
subnet mask255.255.254.0
wildcard0.0.1.255
addresses512
usable hosts510
classA
ipcalc 10.2.66.0/23
address00001010.00000010.01000010.00000000
subnet mask11111111.11111111.11111110.00000000
network00001010.00000010.01000010.00000000
broadcast00001010.00000010.01000011.11111111
green = network part, grey = host part
hex0x0a024200
decimal167920128
reverse dns0.66.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:4200

/23 split into /29 · 64 subnets

close ×
#networkhost rangebroadcast
110.2.66.0/2910.2.66.1 – 10.2.66.610.2.66.7
210.2.66.8/2910.2.66.9 – 10.2.66.1410.2.66.15
310.2.66.16/2910.2.66.17 – 10.2.66.2210.2.66.23
410.2.66.24/2910.2.66.25 – 10.2.66.3010.2.66.31
510.2.66.32/2910.2.66.33 – 10.2.66.3810.2.66.39
610.2.66.40/2910.2.66.41 – 10.2.66.4610.2.66.47
710.2.66.48/2910.2.66.49 – 10.2.66.5410.2.66.55
810.2.66.56/2910.2.66.57 – 10.2.66.6210.2.66.63
910.2.66.64/2910.2.66.65 – 10.2.66.7010.2.66.71
1010.2.66.72/2910.2.66.73 – 10.2.66.7810.2.66.79
1110.2.66.80/2910.2.66.81 – 10.2.66.8610.2.66.87
1210.2.66.88/2910.2.66.89 – 10.2.66.9410.2.66.95
1310.2.66.96/2910.2.66.97 – 10.2.66.10210.2.66.103
1410.2.66.104/2910.2.66.105 – 10.2.66.11010.2.66.111
1510.2.66.112/2910.2.66.113 – 10.2.66.11810.2.66.119
1610.2.66.120/2910.2.66.121 – 10.2.66.12610.2.66.127
1710.2.66.128/2910.2.66.129 – 10.2.66.13410.2.66.135
1810.2.66.136/2910.2.66.137 – 10.2.66.14210.2.66.143
1910.2.66.144/2910.2.66.145 – 10.2.66.15010.2.66.151
2010.2.66.152/2910.2.66.153 – 10.2.66.15810.2.66.159
2110.2.66.160/2910.2.66.161 – 10.2.66.16610.2.66.167
2210.2.66.168/2910.2.66.169 – 10.2.66.17410.2.66.175
2310.2.66.176/2910.2.66.177 – 10.2.66.18210.2.66.183
2410.2.66.184/2910.2.66.185 – 10.2.66.19010.2.66.191
2510.2.66.192/2910.2.66.193 – 10.2.66.19810.2.66.199
2610.2.66.200/2910.2.66.201 – 10.2.66.20610.2.66.207
2710.2.66.208/2910.2.66.209 – 10.2.66.21410.2.66.215
2810.2.66.216/2910.2.66.217 – 10.2.66.22210.2.66.223
2910.2.66.224/2910.2.66.225 – 10.2.66.23010.2.66.231
3010.2.66.232/2910.2.66.233 – 10.2.66.23810.2.66.239
3110.2.66.240/2910.2.66.241 – 10.2.66.24610.2.66.247
3210.2.66.248/2910.2.66.249 – 10.2.66.25410.2.66.255
3310.2.67.0/2910.2.67.1 – 10.2.67.610.2.67.7
3410.2.67.8/2910.2.67.9 – 10.2.67.1410.2.67.15
3510.2.67.16/2910.2.67.17 – 10.2.67.2210.2.67.23
3610.2.67.24/2910.2.67.25 – 10.2.67.3010.2.67.31
3710.2.67.32/2910.2.67.33 – 10.2.67.3810.2.67.39
3810.2.67.40/2910.2.67.41 – 10.2.67.4610.2.67.47
3910.2.67.48/2910.2.67.49 – 10.2.67.5410.2.67.55
4010.2.67.56/2910.2.67.57 – 10.2.67.6210.2.67.63
4110.2.67.64/2910.2.67.65 – 10.2.67.7010.2.67.71
4210.2.67.72/2910.2.67.73 – 10.2.67.7810.2.67.79
4310.2.67.80/2910.2.67.81 – 10.2.67.8610.2.67.87
4410.2.67.88/2910.2.67.89 – 10.2.67.9410.2.67.95
4510.2.67.96/2910.2.67.97 – 10.2.67.10210.2.67.103
4610.2.67.104/2910.2.67.105 – 10.2.67.11010.2.67.111
4710.2.67.112/2910.2.67.113 – 10.2.67.11810.2.67.119
4810.2.67.120/2910.2.67.121 – 10.2.67.12610.2.67.127
4910.2.67.128/2910.2.67.129 – 10.2.67.13410.2.67.135
5010.2.67.136/2910.2.67.137 – 10.2.67.14210.2.67.143
5110.2.67.144/2910.2.67.145 – 10.2.67.15010.2.67.151
5210.2.67.152/2910.2.67.153 – 10.2.67.15810.2.67.159
5310.2.67.160/2910.2.67.161 – 10.2.67.16610.2.67.167
5410.2.67.168/2910.2.67.169 – 10.2.67.17410.2.67.175
5510.2.67.176/2910.2.67.177 – 10.2.67.18210.2.67.183
5610.2.67.184/2910.2.67.185 – 10.2.67.19010.2.67.191
5710.2.67.192/2910.2.67.193 – 10.2.67.19810.2.67.199
5810.2.67.200/2910.2.67.201 – 10.2.67.20610.2.67.207
5910.2.67.208/2910.2.67.209 – 10.2.67.21410.2.67.215
6010.2.67.216/2910.2.67.217 – 10.2.67.22210.2.67.223
6110.2.67.224/2910.2.67.225 – 10.2.67.23010.2.67.231
6210.2.67.232/2910.2.67.233 – 10.2.67.23810.2.67.239
6310.2.67.240/2910.2.67.241 – 10.2.67.24610.2.67.247
6410.2.67.248/2910.2.67.249 – 10.2.67.25410.2.67.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /23
/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-
/23255.255.254.05125101
/24255.255.255.02562542 split →
/25255.255.255.1281281264 split →
/26255.255.255.19264628 split →
/27255.255.255.224323016 split →
/28255.255.255.240161432 split →
/29255.255.255.2488664 split →
/30255.255.255.25242128 split →
/31255.255.255.25422256 split →
/32255.255.255.25511512 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 →