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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)10.2.72.64/27
network10.2.72.64/27
broadcast10.2.72.95
first host10.2.72.65
last host10.2.72.94
subnet mask255.255.255.224
wildcard0.0.0.31
addresses32
usable hosts30
classA
ipcalc 10.2.72.64/27
address00001010.00000010.01001000.01000000
subnet mask11111111.11111111.11111111.11100000
network00001010.00000010.01001000.01000000
broadcast00001010.00000010.01001000.01011111
green = network part, grey = host part
hex0x0a024840
decimal167921728
reverse dns64.72.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:4840

/27 split into /31 · 16 subnets

close ×
#networkhost rangebroadcast
110.2.72.64/3110.2.72.64 – 10.2.72.6510.2.72.65
210.2.72.66/3110.2.72.66 – 10.2.72.6710.2.72.67
310.2.72.68/3110.2.72.68 – 10.2.72.6910.2.72.69
410.2.72.70/3110.2.72.70 – 10.2.72.7110.2.72.71
510.2.72.72/3110.2.72.72 – 10.2.72.7310.2.72.73
610.2.72.74/3110.2.72.74 – 10.2.72.7510.2.72.75
710.2.72.76/3110.2.72.76 – 10.2.72.7710.2.72.77
810.2.72.78/3110.2.72.78 – 10.2.72.7910.2.72.79
910.2.72.80/3110.2.72.80 – 10.2.72.8110.2.72.81
1010.2.72.82/3110.2.72.82 – 10.2.72.8310.2.72.83
1110.2.72.84/3110.2.72.84 – 10.2.72.8510.2.72.85
1210.2.72.86/3110.2.72.86 – 10.2.72.8710.2.72.87
1310.2.72.88/3110.2.72.88 – 10.2.72.8910.2.72.89
1410.2.72.90/3110.2.72.90 – 10.2.72.9110.2.72.91
1510.2.72.92/3110.2.72.92 – 10.2.72.9310.2.72.93
1610.2.72.94/3110.2.72.94 – 10.2.72.9510.2.72.95
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 →