Free online calculator

IPv4 Subnet Calculator

Calculate an IPv4 network address, subnet mask, broadcast address, host range and usable hosts for any CIDR prefix.

✓ Instant results✓ No sign-up✓ Runs in your browser

Prefixes from /0 through /32 are supported.

How it works

Formula and method

Network = IP bitwise AND subnet mask. Broadcast = network bitwise OR the inverted mask.

Worked example

192.168.1.10/24 has network 192.168.1.0 and broadcast 192.168.1.255.

Assumptions

  • /31 follows RFC 3021 point-to-point semantics with two usable addresses.
  • /32 represents one host route.

Reference sources

Reviewed and updated 2026-07-14

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