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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)192.168.1.0/27
network192.168.1.0/27
broadcast192.168.1.31
first host192.168.1.1
last host192.168.1.30
subnet mask255.255.255.224
wildcard0.0.0.31
addresses32
usable hosts30
classC
ipcalc 192.168.1.0/27
address11000000.10101000.00000001.00000000
subnet mask11111111.11111111.11111111.11100000
network11000000.10101000.00000001.00000000
broadcast11000000.10101000.00000001.00011111
green = network part, grey = host part
hex0xc0a80100
decimal3232235776
reverse dns0.1.168.192.in-addr.arpa
ipv4-mapped::ffff:c0a8:100

/27 split into /31 · 16 subnets

close ×
#networkhost rangebroadcast
1192.168.1.0/31192.168.1.0 – 192.168.1.1192.168.1.1
2192.168.1.2/31192.168.1.2 – 192.168.1.3192.168.1.3
3192.168.1.4/31192.168.1.4 – 192.168.1.5192.168.1.5
4192.168.1.6/31192.168.1.6 – 192.168.1.7192.168.1.7
5192.168.1.8/31192.168.1.8 – 192.168.1.9192.168.1.9
6192.168.1.10/31192.168.1.10 – 192.168.1.11192.168.1.11
7192.168.1.12/31192.168.1.12 – 192.168.1.13192.168.1.13
8192.168.1.14/31192.168.1.14 – 192.168.1.15192.168.1.15
9192.168.1.16/31192.168.1.16 – 192.168.1.17192.168.1.17
10192.168.1.18/31192.168.1.18 – 192.168.1.19192.168.1.19
11192.168.1.20/31192.168.1.20 – 192.168.1.21192.168.1.21
12192.168.1.22/31192.168.1.22 – 192.168.1.23192.168.1.23
13192.168.1.24/31192.168.1.24 – 192.168.1.25192.168.1.25
14192.168.1.26/31192.168.1.26 – 192.168.1.27192.168.1.27
15192.168.1.28/31192.168.1.28 – 192.168.1.29192.168.1.29
16192.168.1.30/31192.168.1.30 – 192.168.1.31192.168.1.31
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 →