IPv4 Subnet Calculator

Network address, broadcast, host range, wildcard mask and binary breakdown for any IPv4 CIDR block.

Accepts 10.0.0.5/26, 10.0.0.5 255.255.255.192, or a bare IP.

Results for 198.51.100.8/30

198.51.100.8/30 is the network in CIDR notation · Documentation (TEST-NET-2) (RFC 5737)
Network address
198.51.100.8
Broadcast address
198.51.100.11
Subnet mask
255.255.255.252
Wildcard mask
0.0.0.3
Total addresses
4
Usable hosts
2 (excludes network & broadcast)
First usable host
198.51.100.9
Last usable host
198.51.100.10
CIDR notation
198.51.100.8/30
IP type
Documentation (TEST-NET-2) (RFC 5737)

How the bits line up

Octets (binary)
IP address11000110001100110110010000001000
Subnet mask11111111111111111111111111111100
Network11000110001100110110010000001000
Broadcast11000110001100110110010000001011

The mask's 30 leading ones select the network portion; the remaining 2 bits are available for hosts.

Keep exploring

See every fact about the /30 subnet mask, plan multiple subnets with the VLSM calculator, or convert ranges on the range-to-CIDR tool.