Networking
CIDR / Subnet Calculator
Calculate IPv4 network and broadcast addresses, usable host boundaries, subnet masks, wildcard masks, and binary bit allocation locally.
● LOCAL
● NO NETWORK
● RFC 4632 (CIDR)
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About this tool
What it does
Calculates Classless Inter-Domain Routing (CIDR) IPv4 subnet parameters based on standard 32-bit bitwise masks (RFC 4632). Determines the network identifier, broadcast destination, first/last host boundaries, and host capacity for any prefix length from /0 to /32.
No data leaves your browser. Subnet calculations use 32-bit unsigned integer bitwise operations locally in your browser.
StandardRFC 4632 (Classless Inter-domain Routing)
ProtocolIPv4 (32-bit address space)
Network transferNone
Special Cases
- /31 Subnets (RFC 3021): Point-to-point links with 2 usable host addresses (no dedicated network or broadcast addresses).
- /32 Subnets: Single host route with exactly 1 usable IP address.