# Subnet Calculator

> Bit-Exact IPv4, IPv6, VLSM, Supernetting & Overlap Detection

Free subnet calculator for IPv4 and IPv6. Bit-exact CIDR, VLSM, supernetting, overlap detection. No signup. AI cannot reliably compute subnets - we do.

URL: https://tools.scoreroute.com/tools/subnet-calculator/

Markdown: https://tools.scoreroute.com/tools/subnet-calculator/.md

## IPv4 Subnet Calculator

## IPv6 Subnet Calculator

## VLSM Planner

Allocate variable-length subnets from a parent block. Enter the parent network, then list the host requirements.

## Supernetting (Route Summarization)

Paste multiple networks (one per line) to find the smallest CIDR that contains them all.

## Subnet Splitter

Divide a parent network into N equal subnets. Useful for planning address allocation.

## Overlap Detection

Check if two networks overlap, contain each other, or are identical. Critical for firewall rule audits and routing table analysis.