IT & Developers
Subnet Calculator
Calculate subnet masks and 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 Subnet Calculator do?
It helps you calculate subnet masks and ranges.
What inputs do I need?
Enter IP address and Subnet mask.
Are decimals supported?
Yes, you can use decimal values where appropriate.
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About this tool
This Subnet Calculator turns your inputs into practical results. Provide IP address and Subnet mask to calculate Prefix length and Network address.
Adjust values to compare scenarios and see how sensitive the result is. The calculation uses the numbers as entered, so double-check units and expect small differences from rounding in the displayed totals.