IT & Developers
CIDR Calculator
Calculate CIDR notation and IP ranges
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
Frequently asked questions
What does the CIDR Calculator do?
It helps you calculate CIDR notation and IP ranges.
What inputs do I need?
Enter IP address and Prefix length.
Are decimals supported?
Yes, you can use decimal values where appropriate.
Related tools
About this tool
Inputs
- IP address
- Prefix length
Results
- Subnet mask
- Network address
- Broadcast address
- First host
- Last host
- Total hosts
- Error
You do not need a spreadsheet to calculate cidr notation and ip ranges. This CIDR Calculator gives you the answer in seconds. Developer tools automate tedious transformations so you can focus on the logic that matters. Standard encoding transforms data into a portable format without changing its meaning. All you need to supply is ip address and prefix length.
From there, the tool determines subnet mask, network address, broadcast address and other key metrics. Having a dedicated tool to calculate cidr notation and ip ranges saves time you would otherwise spend searching for formulas or setting up a spreadsheet. Never confuse encoding with encryption — encoding is reversible by design and provides no security. Correct data handling prevents corruption, security vulnerabilities, and interoperability issues. Change one variable while holding the others constant to isolate its impact. This sensitivity check is often more informative than a single result.