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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)10.2.45.128/25
network10.2.45.128/25
broadcast10.2.45.255
first host10.2.45.129
last host10.2.45.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.2.45.128/25
address00001010.00000010.00101101.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000010.00101101.10000000
broadcast00001010.00000010.00101101.11111111
green = network part, grey = host part
hex0x0a022d80
decimal167914880
reverse dns128.45.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:2d80

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
110.2.45.128/3010.2.45.129 – 10.2.45.13010.2.45.131
210.2.45.132/3010.2.45.133 – 10.2.45.13410.2.45.135
310.2.45.136/3010.2.45.137 – 10.2.45.13810.2.45.139
410.2.45.140/3010.2.45.141 – 10.2.45.14210.2.45.143
510.2.45.144/3010.2.45.145 – 10.2.45.14610.2.45.147
610.2.45.148/3010.2.45.149 – 10.2.45.15010.2.45.151
710.2.45.152/3010.2.45.153 – 10.2.45.15410.2.45.155
810.2.45.156/3010.2.45.157 – 10.2.45.15810.2.45.159
910.2.45.160/3010.2.45.161 – 10.2.45.16210.2.45.163
1010.2.45.164/3010.2.45.165 – 10.2.45.16610.2.45.167
1110.2.45.168/3010.2.45.169 – 10.2.45.17010.2.45.171
1210.2.45.172/3010.2.45.173 – 10.2.45.17410.2.45.175
1310.2.45.176/3010.2.45.177 – 10.2.45.17810.2.45.179
1410.2.45.180/3010.2.45.181 – 10.2.45.18210.2.45.183
1510.2.45.184/3010.2.45.185 – 10.2.45.18610.2.45.187
1610.2.45.188/3010.2.45.189 – 10.2.45.19010.2.45.191
1710.2.45.192/3010.2.45.193 – 10.2.45.19410.2.45.195
1810.2.45.196/3010.2.45.197 – 10.2.45.19810.2.45.199
1910.2.45.200/3010.2.45.201 – 10.2.45.20210.2.45.203
2010.2.45.204/3010.2.45.205 – 10.2.45.20610.2.45.207
2110.2.45.208/3010.2.45.209 – 10.2.45.21010.2.45.211
2210.2.45.212/3010.2.45.213 – 10.2.45.21410.2.45.215
2310.2.45.216/3010.2.45.217 – 10.2.45.21810.2.45.219
2410.2.45.220/3010.2.45.221 – 10.2.45.22210.2.45.223
2510.2.45.224/3010.2.45.225 – 10.2.45.22610.2.45.227
2610.2.45.228/3010.2.45.229 – 10.2.45.23010.2.45.231
2710.2.45.232/3010.2.45.233 – 10.2.45.23410.2.45.235
2810.2.45.236/3010.2.45.237 – 10.2.45.23810.2.45.239
2910.2.45.240/3010.2.45.241 – 10.2.45.24210.2.45.243
3010.2.45.244/3010.2.45.245 – 10.2.45.24610.2.45.247
3110.2.45.248/3010.2.45.249 – 10.2.45.25010.2.45.251
3210.2.45.252/3010.2.45.253 – 10.2.45.25410.2.45.255
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 →