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)172.16.1.128/27
network172.16.1.128/27
broadcast172.16.1.159
first host172.16.1.129
last host172.16.1.158
subnet mask255.255.255.224
wildcard0.0.0.31
addresses32
usable hosts30
classB
ipcalc 172.16.1.128/27
address10101100.00010000.00000001.10000000
subnet mask11111111.11111111.11111111.11100000
network10101100.00010000.00000001.10000000
broadcast10101100.00010000.00000001.10011111
green = network part, grey = host part
hex0xac100180
decimal2886730112
reverse dns128.1.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:180

/27 split into /32 · 32 subnets

close ×
#networkhost rangebroadcast
1172.16.1.128/32172.16.1.128 – 172.16.1.128172.16.1.128
2172.16.1.129/32172.16.1.129 – 172.16.1.129172.16.1.129
3172.16.1.130/32172.16.1.130 – 172.16.1.130172.16.1.130
4172.16.1.131/32172.16.1.131 – 172.16.1.131172.16.1.131
5172.16.1.132/32172.16.1.132 – 172.16.1.132172.16.1.132
6172.16.1.133/32172.16.1.133 – 172.16.1.133172.16.1.133
7172.16.1.134/32172.16.1.134 – 172.16.1.134172.16.1.134
8172.16.1.135/32172.16.1.135 – 172.16.1.135172.16.1.135
9172.16.1.136/32172.16.1.136 – 172.16.1.136172.16.1.136
10172.16.1.137/32172.16.1.137 – 172.16.1.137172.16.1.137
11172.16.1.138/32172.16.1.138 – 172.16.1.138172.16.1.138
12172.16.1.139/32172.16.1.139 – 172.16.1.139172.16.1.139
13172.16.1.140/32172.16.1.140 – 172.16.1.140172.16.1.140
14172.16.1.141/32172.16.1.141 – 172.16.1.141172.16.1.141
15172.16.1.142/32172.16.1.142 – 172.16.1.142172.16.1.142
16172.16.1.143/32172.16.1.143 – 172.16.1.143172.16.1.143
17172.16.1.144/32172.16.1.144 – 172.16.1.144172.16.1.144
18172.16.1.145/32172.16.1.145 – 172.16.1.145172.16.1.145
19172.16.1.146/32172.16.1.146 – 172.16.1.146172.16.1.146
20172.16.1.147/32172.16.1.147 – 172.16.1.147172.16.1.147
21172.16.1.148/32172.16.1.148 – 172.16.1.148172.16.1.148
22172.16.1.149/32172.16.1.149 – 172.16.1.149172.16.1.149
23172.16.1.150/32172.16.1.150 – 172.16.1.150172.16.1.150
24172.16.1.151/32172.16.1.151 – 172.16.1.151172.16.1.151
25172.16.1.152/32172.16.1.152 – 172.16.1.152172.16.1.152
26172.16.1.153/32172.16.1.153 – 172.16.1.153172.16.1.153
27172.16.1.154/32172.16.1.154 – 172.16.1.154172.16.1.154
28172.16.1.155/32172.16.1.155 – 172.16.1.155172.16.1.155
29172.16.1.156/32172.16.1.156 – 172.16.1.156172.16.1.156
30172.16.1.157/32172.16.1.157 – 172.16.1.157172.16.1.157
31172.16.1.158/32172.16.1.158 – 172.16.1.158172.16.1.158
32172.16.1.159/32172.16.1.159 – 172.16.1.159172.16.1.159
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /27
/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-
/25255.255.255.128128126-
/26255.255.255.1926462-
/27255.255.255.22432301
/28255.255.255.24016142 split →
/29255.255.255.248864 split →
/30255.255.255.252428 split →
/31255.255.255.2542216 split →
/32255.255.255.2551132 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 →