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.
Related tools
About this tool
Inputs
- IP address
- Subnet mask
Results
- Prefix length
- Network address
- Broadcast address
- First host
- Last host
- Total hosts
- Error
You do not need a spreadsheet to calculate subnet masks and ranges. This Subnet Calculator gives you the answer in seconds. Type in ip address and subnet mask. The computation runs immediately, giving you prefix length, network address, broadcast address and other key metrics. Correct data handling prevents corruption, security vulnerabilities, and interoperability issues.
Output format follows the relevant specification, so it integrates directly with other tools and systems. People frequently need to calculate subnet masks and ranges but lack a quick way to do it — this tool fills that gap. Never confuse encoding with encryption — encoding is reversible by design and provides no security. Industry standards define the rules these tools follow — consistent output means fewer surprises in production. If the result surprises you, revisit your inputs — a mistyped digit or wrong unit is usually the culprit.