What is the CIDR / Subnet Calculator?
Compute network, broadcast and host range from CIDR. The CIDR / Subnet Calculator is a free online tool that works instantly in your browser — no installation, no signup and nothing to upload. It sits alongside other Network tools on DevNibble such as IPv4 Converter, IPv6 Validator & Expander, MAC Address Formatter.
How to use the CIDR / Subnet Calculator
- Enter your values in the fields.
- The result is calculated instantly as you type.
- Copy the output.
Features
- Runs 100% in your browser — your data is never uploaded or stored.
- Free forever, with no account, no ads and no tracking.
- Copy or download your result in one click.
- Fast and responsive on desktop, tablet and mobile.
Frequently asked questions
Is the CIDR / Subnet Calculator free to use?
Yes — CIDR / Subnet Calculator is completely free with no sign-up, no ads and no limit on how many times you can use it.
Is my data private when I use the CIDR / Subnet Calculator?
Everything happens locally in your browser. Your input is never sent to a server, which makes CIDR / Subnet Calculator safe to use with private or sensitive data.
How do I use the CIDR / Subnet Calculator?
Choose your options and click Generate. Every result can be copied with a single click.
Are the generated values unique?
CIDR / Subnet Calculator generates fresh values locally each time you run it, using secure randomness where it matters. Compute network, broadcast and host range from CIDR.