CIDR calculator

Work out the network and broadcast addresses, the usable range, the masks and how a block splits into subnets. Handles the cases most calculators get wrong, including /31 point-to-point links and /0.

CIDR block

Network address: 10.0.0.0
Broadcast address: 10.0.255.255
Usable range: 10.0.0.1 – 10.0.255.254
Subnet mask: 255.255.0.0
Wildcard mask: 0.0.255.255
Total addresses: 65,536
Usable addresses: 65,534
Scope: Private (RFC 1918, 10/8)

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