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CIDR Calculator

Paste CIDR notation. Instant decode to mask, network, and host range.

CIDR10.0.0.0/16
Mask255.255.0.0
Wildcard0.0.255.255
Network10.0.0.0
Broadcast10.0.255.255
Usable range10.0.0.1 – 10.0.255.254
Usable hosts65534

How to read the result

Prefix length = count of network bits. /16 leaves 16 host bits = 65,536 total addresses minus 2.

Example

10.0.0.5/16 → network 10.0.0.0/16, mask 255.255.0.0, 65,534 usable hosts

FAQ

CIDR vs subnet mask?

Same thing, two notations. /24 = 255.255.255.0.

Does host IP matter?

No. Host bits get masked off to find the network.