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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)10.227.152.0/21
network10.227.152.0/21
broadcast10.227.159.255
first host10.227.152.1
last host10.227.159.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.227.152.0/21
address00001010.11100011.10011000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.11100011.10011000.00000000
broadcast00001010.11100011.10011111.11111111
green = network part, grey = host part
hex0x0ae39800
decimal182687744
reverse dns0.152.227.10.in-addr.arpa
ipv4-mapped::ffff:ae3:9800

/21 split into /27 · 64 subnets

close ×
#networkhost rangebroadcast
110.227.152.0/2710.227.152.1 – 10.227.152.3010.227.152.31
210.227.152.32/2710.227.152.33 – 10.227.152.6210.227.152.63
310.227.152.64/2710.227.152.65 – 10.227.152.9410.227.152.95
410.227.152.96/2710.227.152.97 – 10.227.152.12610.227.152.127
510.227.152.128/2710.227.152.129 – 10.227.152.15810.227.152.159
610.227.152.160/2710.227.152.161 – 10.227.152.19010.227.152.191
710.227.152.192/2710.227.152.193 – 10.227.152.22210.227.152.223
810.227.152.224/2710.227.152.225 – 10.227.152.25410.227.152.255
910.227.153.0/2710.227.153.1 – 10.227.153.3010.227.153.31
1010.227.153.32/2710.227.153.33 – 10.227.153.6210.227.153.63
1110.227.153.64/2710.227.153.65 – 10.227.153.9410.227.153.95
1210.227.153.96/2710.227.153.97 – 10.227.153.12610.227.153.127
1310.227.153.128/2710.227.153.129 – 10.227.153.15810.227.153.159
1410.227.153.160/2710.227.153.161 – 10.227.153.19010.227.153.191
1510.227.153.192/2710.227.153.193 – 10.227.153.22210.227.153.223
1610.227.153.224/2710.227.153.225 – 10.227.153.25410.227.153.255
1710.227.154.0/2710.227.154.1 – 10.227.154.3010.227.154.31
1810.227.154.32/2710.227.154.33 – 10.227.154.6210.227.154.63
1910.227.154.64/2710.227.154.65 – 10.227.154.9410.227.154.95
2010.227.154.96/2710.227.154.97 – 10.227.154.12610.227.154.127
2110.227.154.128/2710.227.154.129 – 10.227.154.15810.227.154.159
2210.227.154.160/2710.227.154.161 – 10.227.154.19010.227.154.191
2310.227.154.192/2710.227.154.193 – 10.227.154.22210.227.154.223
2410.227.154.224/2710.227.154.225 – 10.227.154.25410.227.154.255
2510.227.155.0/2710.227.155.1 – 10.227.155.3010.227.155.31
2610.227.155.32/2710.227.155.33 – 10.227.155.6210.227.155.63
2710.227.155.64/2710.227.155.65 – 10.227.155.9410.227.155.95
2810.227.155.96/2710.227.155.97 – 10.227.155.12610.227.155.127
2910.227.155.128/2710.227.155.129 – 10.227.155.15810.227.155.159
3010.227.155.160/2710.227.155.161 – 10.227.155.19010.227.155.191
3110.227.155.192/2710.227.155.193 – 10.227.155.22210.227.155.223
3210.227.155.224/2710.227.155.225 – 10.227.155.25410.227.155.255
3310.227.156.0/2710.227.156.1 – 10.227.156.3010.227.156.31
3410.227.156.32/2710.227.156.33 – 10.227.156.6210.227.156.63
3510.227.156.64/2710.227.156.65 – 10.227.156.9410.227.156.95
3610.227.156.96/2710.227.156.97 – 10.227.156.12610.227.156.127
3710.227.156.128/2710.227.156.129 – 10.227.156.15810.227.156.159
3810.227.156.160/2710.227.156.161 – 10.227.156.19010.227.156.191
3910.227.156.192/2710.227.156.193 – 10.227.156.22210.227.156.223
4010.227.156.224/2710.227.156.225 – 10.227.156.25410.227.156.255
4110.227.157.0/2710.227.157.1 – 10.227.157.3010.227.157.31
4210.227.157.32/2710.227.157.33 – 10.227.157.6210.227.157.63
4310.227.157.64/2710.227.157.65 – 10.227.157.9410.227.157.95
4410.227.157.96/2710.227.157.97 – 10.227.157.12610.227.157.127
4510.227.157.128/2710.227.157.129 – 10.227.157.15810.227.157.159
4610.227.157.160/2710.227.157.161 – 10.227.157.19010.227.157.191
4710.227.157.192/2710.227.157.193 – 10.227.157.22210.227.157.223
4810.227.157.224/2710.227.157.225 – 10.227.157.25410.227.157.255
4910.227.158.0/2710.227.158.1 – 10.227.158.3010.227.158.31
5010.227.158.32/2710.227.158.33 – 10.227.158.6210.227.158.63
5110.227.158.64/2710.227.158.65 – 10.227.158.9410.227.158.95
5210.227.158.96/2710.227.158.97 – 10.227.158.12610.227.158.127
5310.227.158.128/2710.227.158.129 – 10.227.158.15810.227.158.159
5410.227.158.160/2710.227.158.161 – 10.227.158.19010.227.158.191
5510.227.158.192/2710.227.158.193 – 10.227.158.22210.227.158.223
5610.227.158.224/2710.227.158.225 – 10.227.158.25410.227.158.255
5710.227.159.0/2710.227.159.1 – 10.227.159.3010.227.159.31
5810.227.159.32/2710.227.159.33 – 10.227.159.6210.227.159.63
5910.227.159.64/2710.227.159.65 – 10.227.159.9410.227.159.95
6010.227.159.96/2710.227.159.97 – 10.227.159.12610.227.159.127
6110.227.159.128/2710.227.159.129 – 10.227.159.15810.227.159.159
6210.227.159.160/2710.227.159.161 – 10.227.159.19010.227.159.191
6310.227.159.192/2710.227.159.193 – 10.227.159.22210.227.159.223
6410.227.159.224/2710.227.159.225 – 10.227.159.25410.227.159.255
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 →