Subnetting workflow depth

v10.81 connects IPv4/IPv6 inspection, exact range-to-CIDR conversion, VLSM allocation, fixed-size splitting, route aggregation, binary/reference views, and practice. Deterministic address math stays local in the browser, with copy/export where it helps real network planning.

How to use this VLSM Calculator

Design variable-length IPv4 subnets from one parent CIDR and multiple host requirements.

Enter, paste, upload, or choose the inputs shown in the tool above.
Adjust the available options for the result you need.
Review the output before copying, downloading, or using it elsewhere.

What this tool does

Enter a parent network plus named host counts to allocate largest-first VLSM subnets with network, host range, broadcast, capacity, waste, copy, and CSV output.

Practical tips and limits

Review the inputs and result before using the output elsewhere. Keep the original data when the operation changes or replaces content.