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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)10.0.88.0/21
network10.0.88.0/21
broadcast10.0.95.255
first host10.0.88.1
last host10.0.95.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.0.88.0/21
address00001010.00000000.01011000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000000.01011000.00000000
broadcast00001010.00000000.01011111.11111111
green = network part, grey = host part
hex0x0a005800
decimal167794688
reverse dns0.88.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:5800

/21 split into /27 · 64 subnets

close ×
#networkhost rangebroadcast
110.0.88.0/2710.0.88.1 – 10.0.88.3010.0.88.31
210.0.88.32/2710.0.88.33 – 10.0.88.6210.0.88.63
310.0.88.64/2710.0.88.65 – 10.0.88.9410.0.88.95
410.0.88.96/2710.0.88.97 – 10.0.88.12610.0.88.127
510.0.88.128/2710.0.88.129 – 10.0.88.15810.0.88.159
610.0.88.160/2710.0.88.161 – 10.0.88.19010.0.88.191
710.0.88.192/2710.0.88.193 – 10.0.88.22210.0.88.223
810.0.88.224/2710.0.88.225 – 10.0.88.25410.0.88.255
910.0.89.0/2710.0.89.1 – 10.0.89.3010.0.89.31
1010.0.89.32/2710.0.89.33 – 10.0.89.6210.0.89.63
1110.0.89.64/2710.0.89.65 – 10.0.89.9410.0.89.95
1210.0.89.96/2710.0.89.97 – 10.0.89.12610.0.89.127
1310.0.89.128/2710.0.89.129 – 10.0.89.15810.0.89.159
1410.0.89.160/2710.0.89.161 – 10.0.89.19010.0.89.191
1510.0.89.192/2710.0.89.193 – 10.0.89.22210.0.89.223
1610.0.89.224/2710.0.89.225 – 10.0.89.25410.0.89.255
1710.0.90.0/2710.0.90.1 – 10.0.90.3010.0.90.31
1810.0.90.32/2710.0.90.33 – 10.0.90.6210.0.90.63
1910.0.90.64/2710.0.90.65 – 10.0.90.9410.0.90.95
2010.0.90.96/2710.0.90.97 – 10.0.90.12610.0.90.127
2110.0.90.128/2710.0.90.129 – 10.0.90.15810.0.90.159
2210.0.90.160/2710.0.90.161 – 10.0.90.19010.0.90.191
2310.0.90.192/2710.0.90.193 – 10.0.90.22210.0.90.223
2410.0.90.224/2710.0.90.225 – 10.0.90.25410.0.90.255
2510.0.91.0/2710.0.91.1 – 10.0.91.3010.0.91.31
2610.0.91.32/2710.0.91.33 – 10.0.91.6210.0.91.63
2710.0.91.64/2710.0.91.65 – 10.0.91.9410.0.91.95
2810.0.91.96/2710.0.91.97 – 10.0.91.12610.0.91.127
2910.0.91.128/2710.0.91.129 – 10.0.91.15810.0.91.159
3010.0.91.160/2710.0.91.161 – 10.0.91.19010.0.91.191
3110.0.91.192/2710.0.91.193 – 10.0.91.22210.0.91.223
3210.0.91.224/2710.0.91.225 – 10.0.91.25410.0.91.255
3310.0.92.0/2710.0.92.1 – 10.0.92.3010.0.92.31
3410.0.92.32/2710.0.92.33 – 10.0.92.6210.0.92.63
3510.0.92.64/2710.0.92.65 – 10.0.92.9410.0.92.95
3610.0.92.96/2710.0.92.97 – 10.0.92.12610.0.92.127
3710.0.92.128/2710.0.92.129 – 10.0.92.15810.0.92.159
3810.0.92.160/2710.0.92.161 – 10.0.92.19010.0.92.191
3910.0.92.192/2710.0.92.193 – 10.0.92.22210.0.92.223
4010.0.92.224/2710.0.92.225 – 10.0.92.25410.0.92.255
4110.0.93.0/2710.0.93.1 – 10.0.93.3010.0.93.31
4210.0.93.32/2710.0.93.33 – 10.0.93.6210.0.93.63
4310.0.93.64/2710.0.93.65 – 10.0.93.9410.0.93.95
4410.0.93.96/2710.0.93.97 – 10.0.93.12610.0.93.127
4510.0.93.128/2710.0.93.129 – 10.0.93.15810.0.93.159
4610.0.93.160/2710.0.93.161 – 10.0.93.19010.0.93.191
4710.0.93.192/2710.0.93.193 – 10.0.93.22210.0.93.223
4810.0.93.224/2710.0.93.225 – 10.0.93.25410.0.93.255
4910.0.94.0/2710.0.94.1 – 10.0.94.3010.0.94.31
5010.0.94.32/2710.0.94.33 – 10.0.94.6210.0.94.63
5110.0.94.64/2710.0.94.65 – 10.0.94.9410.0.94.95
5210.0.94.96/2710.0.94.97 – 10.0.94.12610.0.94.127
5310.0.94.128/2710.0.94.129 – 10.0.94.15810.0.94.159
5410.0.94.160/2710.0.94.161 – 10.0.94.19010.0.94.191
5510.0.94.192/2710.0.94.193 – 10.0.94.22210.0.94.223
5610.0.94.224/2710.0.94.225 – 10.0.94.25410.0.94.255
5710.0.95.0/2710.0.95.1 – 10.0.95.3010.0.95.31
5810.0.95.32/2710.0.95.33 – 10.0.95.6210.0.95.63
5910.0.95.64/2710.0.95.65 – 10.0.95.9410.0.95.95
6010.0.95.96/2710.0.95.97 – 10.0.95.12610.0.95.127
6110.0.95.128/2710.0.95.129 – 10.0.95.15810.0.95.159
6210.0.95.160/2710.0.95.161 – 10.0.95.19010.0.95.191
6310.0.95.192/2710.0.95.193 – 10.0.95.22210.0.95.223
6410.0.95.224/2710.0.95.225 – 10.0.95.25410.0.95.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /21
/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-
/21255.255.248.02,0482,0461
/22255.255.252.01,0241,0222 split →
/23255.255.254.05125104 split →
/24255.255.255.02562548 split →
/25255.255.255.12812812616 split →
/26255.255.255.192646232 split →
/27255.255.255.224323064 split →
/28255.255.255.2401614128 split →
/29255.255.255.24886256 split →
/30255.255.255.25242512 split →
/31255.255.255.254221,024 split →
/32255.255.255.255112,048 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 →