How Stair Stringer Calculator Works
Estimate stair rise, run, stringer length and stair angle from floor height and tread dimensions. The calculation runs locally in your browser, so the values entered on this page are not sent to a server by the calculator.
Method: stringer length = √(rise² + total run²). Results are estimates and depend on the accuracy and suitability of the inputs.
How to use it
- Enter verified measurements and keep units consistent.
- Calculate the result and test alternative assumptions when comparing scenarios.
- For engineering or safety-critical work, compare the estimate with the applicable code, standard or manufacturer specification.
Common mistakes
- Using nominal dimensions when actual dimensions are required.
- Mixing units or using an unsuitable material/property assumption.
- Treating a preliminary estimate as a final design approval.
Limitations
This calculator provides a mathematical estimate only. Real installations can be affected by temperature, material properties, tolerances, installation method, safety factors, local codes and manufacturer requirements.