Subnet Calculator

What this calculator does

Enter an IPv4 address and a prefix length. The tool returns the network, broadcast, host range, usable host count, netmask and wildcard. /31 is treated as a point-to-point link with two usable addresses. /32 is a single host.

• Usable hosts for a normal network are 2^(32 − prefix) − 2.
• The optional host count picks the smallest prefix that fits that many hosts.
• Nothing is sent to a server. The calculation stays in the browser.