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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)10.2.20.0/23
network10.2.20.0/23
broadcast10.2.21.255
first host10.2.20.1
last host10.2.21.254
subnet mask255.255.254.0
wildcard0.0.1.255
addresses512
usable hosts510
classA
ipcalc 10.2.20.0/23
address00001010.00000010.00010100.00000000
subnet mask11111111.11111111.11111110.00000000
network00001010.00000010.00010100.00000000
broadcast00001010.00000010.00010101.11111111
green = network part, grey = host part
hex0x0a021400
decimal167908352
reverse dns0.20.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:1400

/23 split into /28 · 32 subnets

close ×
#networkhost rangebroadcast
110.2.20.0/2810.2.20.1 – 10.2.20.1410.2.20.15
210.2.20.16/2810.2.20.17 – 10.2.20.3010.2.20.31
310.2.20.32/2810.2.20.33 – 10.2.20.4610.2.20.47
410.2.20.48/2810.2.20.49 – 10.2.20.6210.2.20.63
510.2.20.64/2810.2.20.65 – 10.2.20.7810.2.20.79
610.2.20.80/2810.2.20.81 – 10.2.20.9410.2.20.95
710.2.20.96/2810.2.20.97 – 10.2.20.11010.2.20.111
810.2.20.112/2810.2.20.113 – 10.2.20.12610.2.20.127
910.2.20.128/2810.2.20.129 – 10.2.20.14210.2.20.143
1010.2.20.144/2810.2.20.145 – 10.2.20.15810.2.20.159
1110.2.20.160/2810.2.20.161 – 10.2.20.17410.2.20.175
1210.2.20.176/2810.2.20.177 – 10.2.20.19010.2.20.191
1310.2.20.192/2810.2.20.193 – 10.2.20.20610.2.20.207
1410.2.20.208/2810.2.20.209 – 10.2.20.22210.2.20.223
1510.2.20.224/2810.2.20.225 – 10.2.20.23810.2.20.239
1610.2.20.240/2810.2.20.241 – 10.2.20.25410.2.20.255
1710.2.21.0/2810.2.21.1 – 10.2.21.1410.2.21.15
1810.2.21.16/2810.2.21.17 – 10.2.21.3010.2.21.31
1910.2.21.32/2810.2.21.33 – 10.2.21.4610.2.21.47
2010.2.21.48/2810.2.21.49 – 10.2.21.6210.2.21.63
2110.2.21.64/2810.2.21.65 – 10.2.21.7810.2.21.79
2210.2.21.80/2810.2.21.81 – 10.2.21.9410.2.21.95
2310.2.21.96/2810.2.21.97 – 10.2.21.11010.2.21.111
2410.2.21.112/2810.2.21.113 – 10.2.21.12610.2.21.127
2510.2.21.128/2810.2.21.129 – 10.2.21.14210.2.21.143
2610.2.21.144/2810.2.21.145 – 10.2.21.15810.2.21.159
2710.2.21.160/2810.2.21.161 – 10.2.21.17410.2.21.175
2810.2.21.176/2810.2.21.177 – 10.2.21.19010.2.21.191
2910.2.21.192/2810.2.21.193 – 10.2.21.20610.2.21.207
3010.2.21.208/2810.2.21.209 – 10.2.21.22210.2.21.223
3110.2.21.224/2810.2.21.225 – 10.2.21.23810.2.21.239
3210.2.21.240/2810.2.21.241 – 10.2.21.25410.2.21.255
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 →