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
Try:192.168.1.10/2410.0.0.0/8172.16.5.4/20203.0.113.9/29
IPv6 calculator →
private IP (RFC 1918)172.16.7.128/25
network172.16.7.128/25
broadcast172.16.7.255
first host172.16.7.129
last host172.16.7.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classB
ipcalc 172.16.7.128/25
address10101100.00010000.00000111.10000000
subnet mask11111111.11111111.11111111.10000000
network10101100.00010000.00000111.10000000
broadcast10101100.00010000.00000111.11111111
green = network part, grey = host part
hex0xac100780
decimal2886731648
reverse dns128.7.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:780

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
1172.16.7.128/30172.16.7.129 – 172.16.7.130172.16.7.131
2172.16.7.132/30172.16.7.133 – 172.16.7.134172.16.7.135
3172.16.7.136/30172.16.7.137 – 172.16.7.138172.16.7.139
4172.16.7.140/30172.16.7.141 – 172.16.7.142172.16.7.143
5172.16.7.144/30172.16.7.145 – 172.16.7.146172.16.7.147
6172.16.7.148/30172.16.7.149 – 172.16.7.150172.16.7.151
7172.16.7.152/30172.16.7.153 – 172.16.7.154172.16.7.155
8172.16.7.156/30172.16.7.157 – 172.16.7.158172.16.7.159
9172.16.7.160/30172.16.7.161 – 172.16.7.162172.16.7.163
10172.16.7.164/30172.16.7.165 – 172.16.7.166172.16.7.167
11172.16.7.168/30172.16.7.169 – 172.16.7.170172.16.7.171
12172.16.7.172/30172.16.7.173 – 172.16.7.174172.16.7.175
13172.16.7.176/30172.16.7.177 – 172.16.7.178172.16.7.179
14172.16.7.180/30172.16.7.181 – 172.16.7.182172.16.7.183
15172.16.7.184/30172.16.7.185 – 172.16.7.186172.16.7.187
16172.16.7.188/30172.16.7.189 – 172.16.7.190172.16.7.191
17172.16.7.192/30172.16.7.193 – 172.16.7.194172.16.7.195
18172.16.7.196/30172.16.7.197 – 172.16.7.198172.16.7.199
19172.16.7.200/30172.16.7.201 – 172.16.7.202172.16.7.203
20172.16.7.204/30172.16.7.205 – 172.16.7.206172.16.7.207
21172.16.7.208/30172.16.7.209 – 172.16.7.210172.16.7.211
22172.16.7.212/30172.16.7.213 – 172.16.7.214172.16.7.215
23172.16.7.216/30172.16.7.217 – 172.16.7.218172.16.7.219
24172.16.7.220/30172.16.7.221 – 172.16.7.222172.16.7.223
25172.16.7.224/30172.16.7.225 – 172.16.7.226172.16.7.227
26172.16.7.228/30172.16.7.229 – 172.16.7.230172.16.7.231
27172.16.7.232/30172.16.7.233 – 172.16.7.234172.16.7.235
28172.16.7.236/30172.16.7.237 – 172.16.7.238172.16.7.239
29172.16.7.240/30172.16.7.241 – 172.16.7.242172.16.7.243
30172.16.7.244/30172.16.7.245 – 172.16.7.246172.16.7.247
31172.16.7.248/30172.16.7.249 – 172.16.7.250172.16.7.251
32172.16.7.252/30172.16.7.253 – 172.16.7.254172.16.7.255
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 →