Estimate arc radius and arc length from span and midspan sag (circular arc approximation).
The Sag Calculator is a free online tool that helps you quickly compute values related to sag. Estimate arc radius and arc length from span and midspan sag (circular arc approximation).
This calculator is part of our Construction category, which includes hundreds of specialized tools for construction-related calculations.
Simply enter your values in the fields above and click "Calculate" or watch the results update automatically as you type. All calculations are performed instantly in your browser — no data is sent to any server.
This tool is commonly used alongside other construction calculators. Browse our full collection of Construction calculators to find more tools that can help with your construction calculations.