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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)10.2.158.128/25
network10.2.158.128/25
broadcast10.2.158.255
first host10.2.158.129
last host10.2.158.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.2.158.128/25
address00001010.00000010.10011110.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000010.10011110.10000000
broadcast00001010.00000010.10011110.11111111
green = network part, grey = host part
hex0x0a029e80
decimal167943808
reverse dns128.158.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:9e80

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
110.2.158.128/3010.2.158.129 – 10.2.158.13010.2.158.131
210.2.158.132/3010.2.158.133 – 10.2.158.13410.2.158.135
310.2.158.136/3010.2.158.137 – 10.2.158.13810.2.158.139
410.2.158.140/3010.2.158.141 – 10.2.158.14210.2.158.143
510.2.158.144/3010.2.158.145 – 10.2.158.14610.2.158.147
610.2.158.148/3010.2.158.149 – 10.2.158.15010.2.158.151
710.2.158.152/3010.2.158.153 – 10.2.158.15410.2.158.155
810.2.158.156/3010.2.158.157 – 10.2.158.15810.2.158.159
910.2.158.160/3010.2.158.161 – 10.2.158.16210.2.158.163
1010.2.158.164/3010.2.158.165 – 10.2.158.16610.2.158.167
1110.2.158.168/3010.2.158.169 – 10.2.158.17010.2.158.171
1210.2.158.172/3010.2.158.173 – 10.2.158.17410.2.158.175
1310.2.158.176/3010.2.158.177 – 10.2.158.17810.2.158.179
1410.2.158.180/3010.2.158.181 – 10.2.158.18210.2.158.183
1510.2.158.184/3010.2.158.185 – 10.2.158.18610.2.158.187
1610.2.158.188/3010.2.158.189 – 10.2.158.19010.2.158.191
1710.2.158.192/3010.2.158.193 – 10.2.158.19410.2.158.195
1810.2.158.196/3010.2.158.197 – 10.2.158.19810.2.158.199
1910.2.158.200/3010.2.158.201 – 10.2.158.20210.2.158.203
2010.2.158.204/3010.2.158.205 – 10.2.158.20610.2.158.207
2110.2.158.208/3010.2.158.209 – 10.2.158.21010.2.158.211
2210.2.158.212/3010.2.158.213 – 10.2.158.21410.2.158.215
2310.2.158.216/3010.2.158.217 – 10.2.158.21810.2.158.219
2410.2.158.220/3010.2.158.221 – 10.2.158.22210.2.158.223
2510.2.158.224/3010.2.158.225 – 10.2.158.22610.2.158.227
2610.2.158.228/3010.2.158.229 – 10.2.158.23010.2.158.231
2710.2.158.232/3010.2.158.233 – 10.2.158.23410.2.158.235
2810.2.158.236/3010.2.158.237 – 10.2.158.23810.2.158.239
2910.2.158.240/3010.2.158.241 – 10.2.158.24210.2.158.243
3010.2.158.244/3010.2.158.245 – 10.2.158.24610.2.158.247
3110.2.158.248/3010.2.158.249 – 10.2.158.25010.2.158.251
3210.2.158.252/3010.2.158.253 – 10.2.158.25410.2.158.255
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 →