ip
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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
private IP (RFC 1918)10.4.149.128/25
network10.4.149.128/25
broadcast10.4.149.255
first host10.4.149.129
last host10.4.149.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.4.149.128/25
address00001010.00000100.10010101.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000100.10010101.10000000
broadcast00001010.00000100.10010101.11111111
green = network part, grey = host part
hex0x0a049580
decimal168072576
reverse dns128.149.4.10.in-addr.arpa
ipv4-mapped::ffff:a04:9580

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
110.4.149.128/3010.4.149.129 – 10.4.149.13010.4.149.131
210.4.149.132/3010.4.149.133 – 10.4.149.13410.4.149.135
310.4.149.136/3010.4.149.137 – 10.4.149.13810.4.149.139
410.4.149.140/3010.4.149.141 – 10.4.149.14210.4.149.143
510.4.149.144/3010.4.149.145 – 10.4.149.14610.4.149.147
610.4.149.148/3010.4.149.149 – 10.4.149.15010.4.149.151
710.4.149.152/3010.4.149.153 – 10.4.149.15410.4.149.155
810.4.149.156/3010.4.149.157 – 10.4.149.15810.4.149.159
910.4.149.160/3010.4.149.161 – 10.4.149.16210.4.149.163
1010.4.149.164/3010.4.149.165 – 10.4.149.16610.4.149.167
1110.4.149.168/3010.4.149.169 – 10.4.149.17010.4.149.171
1210.4.149.172/3010.4.149.173 – 10.4.149.17410.4.149.175
1310.4.149.176/3010.4.149.177 – 10.4.149.17810.4.149.179
1410.4.149.180/3010.4.149.181 – 10.4.149.18210.4.149.183
1510.4.149.184/3010.4.149.185 – 10.4.149.18610.4.149.187
1610.4.149.188/3010.4.149.189 – 10.4.149.19010.4.149.191
1710.4.149.192/3010.4.149.193 – 10.4.149.19410.4.149.195
1810.4.149.196/3010.4.149.197 – 10.4.149.19810.4.149.199
1910.4.149.200/3010.4.149.201 – 10.4.149.20210.4.149.203
2010.4.149.204/3010.4.149.205 – 10.4.149.20610.4.149.207
2110.4.149.208/3010.4.149.209 – 10.4.149.21010.4.149.211
2210.4.149.212/3010.4.149.213 – 10.4.149.21410.4.149.215
2310.4.149.216/3010.4.149.217 – 10.4.149.21810.4.149.219
2410.4.149.220/3010.4.149.221 – 10.4.149.22210.4.149.223
2510.4.149.224/3010.4.149.225 – 10.4.149.22610.4.149.227
2610.4.149.228/3010.4.149.229 – 10.4.149.23010.4.149.231
2710.4.149.232/3010.4.149.233 – 10.4.149.23410.4.149.235
2810.4.149.236/3010.4.149.237 – 10.4.149.23810.4.149.239
2910.4.149.240/3010.4.149.241 – 10.4.149.24210.4.149.243
3010.4.149.244/3010.4.149.245 – 10.4.149.24610.4.149.247
3110.4.149.248/3010.4.149.249 – 10.4.149.25010.4.149.251
3210.4.149.252/3010.4.149.253 – 10.4.149.25410.4.149.255
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 →