Network

Supernet Calculator

Find the smallest covering CIDR for an IPv4 start/end range.

Last validated: 2026-02-14

Supernet Calculator finds the minimal supernet that covers multiple child networks. It is useful for summarizing routes and simplifying security policy definitions. The tool helps you collapse complexity while preserving address inclusion requirements. Use it when optimizing route advertisements or ACL entries.

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Input Pattern

Enter values in the left panel, keep units explicit, run the calculation, then copy or share the result. Invalid fields are highlighted immediately.

Supernet Inputs

Result

Covering supernet: 10.0.0.0/22

Range size: 1,024 IPs

How to use this tool

Provide the list of subnets you want to cover.
Run the tool to compute the smallest enclosing supernet.
Validate that resulting coverage is acceptable for your policy scope.

Worked Example

Auto-generated from the tool's current default or entered inputs.

Example Inputs

Start ip: 10.0.0.0
End ip: 10.0.3.255
Supernet: 10.0.0.0/22
Range size: 1024

Expected Outputs

Range size: 1024

Interpretation

Range size is 1024. Use this as a decision input, not as a standalone conclusion.
Confirm unit consistency and operational constraints before applying this result in production or field conditions.

Scenario Compare (A vs B)

Use this to compare two input sets and quantify change in key outputs.

Formula References

IPv4/IPv6 addressing rules and common protocol arithmetic.
DNS/WHOIS/network calls depend on external resolvers and current network state.

Assumptions

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