About IP Subnet Calculator
What It Does
Calculate subnet details from any IPv4 address and CIDR prefix or subnet mask. Instantly see the network address, broadcast, host range, wildcard mask, and IP class. Convert addresses between decimal, binary, hex, integer, and IPv4-mapped IPv6 formats.
Features
- Subnet calculation — network, broadcast, first/last host, total and usable host counts
- Dual input — enter CIDR prefix (/24) or full subnet mask (255.255.255.0)
- IP classification — class (A/B/C/D/E) and type (private, public, loopback, link-local)
- Format conversions — decimal, binary, hex, integer, IPv4-mapped IPv6
- CIDR reference table — all 33 prefix lengths with mask, total IPs, and usable hosts
- Click to copy — click any result value to copy it to clipboard
- Live updates — results recalculate as you type
Privacy
All calculations run in your browser. No IP addresses or network data are sent to any server.