Network
CIDR Calculator
Inspect IPv4 and IPv6 CIDR ranges, exact counts, masks, and host boundaries.
Runs locally in your browserLoading the local workbench…
About this tool
Analyze an existing IPv4 or IPv6 CIDR locally. IPv4 /31 and /32 use modern endpoint semantics, large IPv6 counts remain exact, and IPv6 is never assigned a broadcast address.
Common uses
- Normalize a CIDR network
- Inspect exact first and last addresses
- Calculate IPv4 masks and IPv6 address counts