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IP & Network Tools

CIDR Calculator

Expand IPv4 CIDR notation into its network range, masks and address capacity.

Free browser toolRuns in your browserNo sign-up

IP & Network Tools

CIDR Calculator

Expand IPv4 CIDR notation into its complete network range and address capacity.

Calculation runs locally in your browser. No address is uploaded.

About the CIDR Calculator

CIDR Calculator is a focused network utility for administrators, developers, support teams and people troubleshooting an internet connection. Expand IPv4 CIDR notation into its network range, masks and address capacity.

The calculation runs locally in your browser, so the address is not uploaded.

Results describe public network information and should not be treated as proof of a person's identity or exact physical location.

Key features

  • CIDR notation validation
  • First and last address
  • Subnet and wildcard masks

How to use

  1. 1Enter an IPv4 network in CIDR notation.
  2. 2Select Calculate range.
  3. 3Review the normalized range, masks and capacity.

Examples

CIDR Calculator example
Input: 10.20.30.0/24
Output: 10.20.30.0 through 10.20.30.255

The calculator also accepts a host address inside the network.

Frequently asked questions

Is this tool free?
Yes. It requires no account, payment or software installation.
Are IP location results exact?
No. IP geolocation is approximate and usually identifies a network region, not a home, person or precise device location.
Does this tool expose private network data?
No. This calculator operates entirely on the values in your browser.
Can I use it on mobile?
Yes. Inputs, tables and results adapt to phones, tablets and desktop browsers.

Continue your workflow

Open a related tool to prepare your files or refine the finished result.