Subnet Calculator

Calculate network address, broadcast, host range, and subnet mask from any IPv4 CIDR notation. Results update instantly.

IP Address / CIDR

Prefix length

Common Subnets

Network Address

192.168.1.0

Broadcast Address

192.168.1.255

Subnet Mask

255.255.255.0

Wildcard Mask

0.0.0.255

CIDR Notation

192.168.1.0/24

First Usable Host

192.168.1.1

Last Usable Host

192.168.1.254

Total Addresses

256

Usable Hosts

254

IP Class

Class C

Range Type

Private (RFC 1918)

▶CIDR Reference Table

CIDR	Subnet Mask	Addresses	Usable Hosts
/8	255.0.0.0	16,777,216	16,777,214
/9	255.128.0.0	8,388,608	8,388,606
/10	255.192.0.0	4,194,304	4,194,302
/11	255.224.0.0	2,097,152	2,097,150
/12	255.240.0.0	1,048,576	1,048,574
/13	255.248.0.0	524,288	524,286
/14	255.252.0.0	262,144	262,142
/15	255.254.0.0	131,072	131,070
/16	255.255.0.0	65,536	65,534
/17	255.255.128.0	32,768	32,766
/18	255.255.192.0	16,384	16,382
/19	255.255.224.0	8,192	8,190
/20	255.255.240.0	4,096	4,094
/21	255.255.248.0	2,048	2,046
/22	255.255.252.0	1,024	1,022
/23	255.255.254.0	512	510
/24	255.255.255.0	256	254
/25	255.255.255.128	128	126
/26	255.255.255.192	64	62
/27	255.255.255.224	32	30
/28	255.255.255.240	16	14
/29	255.255.255.248	8	6
/30	255.255.255.252	4	2
/31	255.255.255.254	2	2
/32	255.255.255.255	1	1

CIDR notation combines an IP address with a prefix length (e.g., 192.168.1.0/24).
The prefix length defines how many bits are the network portion — the rest are host bits.
Network address = all host bits set to 0. Broadcast = all host bits set to 1.
Usable hosts = total addresses minus network and broadcast (except /31 and /32 special cases).
Private ranges (RFC 1918): 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.
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