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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)10.0.87.128/25
network10.0.87.128/25
broadcast10.0.87.255
first host10.0.87.129
last host10.0.87.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.0.87.128/25
address00001010.00000000.01010111.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000000.01010111.10000000
broadcast00001010.00000000.01010111.11111111
green = network part, grey = host part
hex0x0a005780
decimal167794560
reverse dns128.87.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:5780

/25 split into /29 · 16 subnets

close ×
#networkhost rangebroadcast
110.0.87.128/2910.0.87.129 – 10.0.87.13410.0.87.135
210.0.87.136/2910.0.87.137 – 10.0.87.14210.0.87.143
310.0.87.144/2910.0.87.145 – 10.0.87.15010.0.87.151
410.0.87.152/2910.0.87.153 – 10.0.87.15810.0.87.159
510.0.87.160/2910.0.87.161 – 10.0.87.16610.0.87.167
610.0.87.168/2910.0.87.169 – 10.0.87.17410.0.87.175
710.0.87.176/2910.0.87.177 – 10.0.87.18210.0.87.183
810.0.87.184/2910.0.87.185 – 10.0.87.19010.0.87.191
910.0.87.192/2910.0.87.193 – 10.0.87.19810.0.87.199
1010.0.87.200/2910.0.87.201 – 10.0.87.20610.0.87.207
1110.0.87.208/2910.0.87.209 – 10.0.87.21410.0.87.215
1210.0.87.216/2910.0.87.217 – 10.0.87.22210.0.87.223
1310.0.87.224/2910.0.87.225 – 10.0.87.23010.0.87.231
1410.0.87.232/2910.0.87.233 – 10.0.87.23810.0.87.239
1510.0.87.240/2910.0.87.241 – 10.0.87.24610.0.87.247
1610.0.87.248/2910.0.87.249 – 10.0.87.25410.0.87.255
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 →