CIDR Calculator
Expand any CIDR block into full network details
100% private. Your files and inputs never leave your device — everything runs locally in your browser.
How to Use CIDR Calculator
Expand any CIDR block into full network details. No signup, no uploads, no watermarks.
- 1
Enter your numbers in the input fields.
- 2
Choose the calculation options or frequency.
- 3
The result updates instantly as you type.
- 4
Review the breakdown, chart, or schedule, and copy the answer.
Why choose CIDR Calculator?
- No uploads — your files never leave your device.
- Free forever with no signup, no watermarks, and no limits.
- Works on any device with a modern browser — no installs.
- Fast, private, and built for getting the job done in seconds.
Frequently Asked Questions
What is CIDR notation?▾
CIDR notation writes an IP address followed by a slash and the number of leading network bits, like 192.168.1.0/24. A /24 block covers 256 addresses.
How many addresses are in a CIDR block?▾
A /prefix block contains 2^(32−prefix) addresses. Usable hosts subtract the network and broadcast addresses, giving 2^(32−prefix) − 2 for prefixes below 31.
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