IP Subnet Netmask Calculator

Calculate IP Subnets and Netmasks

Use these tools to calculate subnets and netmasks. Source at GitHub.

Compatible with Node.js (Common-JS like), Require.js (AMD), and direct use. See readme for instructions.

IP Range Mask Optimizer

This tool calculates optimal netmasks for covering any range of IP addresses. Depending on the range of IP addresses entered, the result can be multiple masks.

CIDR Subnet Mask Calculator

Subnet Mask Calculator