Network / Engineering tools
IPv4 Subnet Calculator
Calculate network boundaries, masks, host ranges, and /31 point-to-point addresses. Work locally without uploading network information.
Runs entirely on your deviceNo uploads, accounts, cookies, or personal tracking.
Calculate subnet
Local processing · no input storage
Enter your data, then select calculate subnet.
Result
Technical reference: RFC 3021
1. Add your data
Enter your network data or load the worked example.
2. Choose the result
Calculate subnet and review the result and assumptions.
3. Save it locally
Copy the result or download it for your engineering workflow.
About this tool
Use IPv4 Subnet Calculator without an upload
Calculate network boundaries, masks, host ranges, and /31 point-to-point addresses. Work locally without uploading network information.
The operation runs in the current browser tab. Tool input is not included in aggregate analytics, and the standalone download makes no analytics requests.