Stair Stringer Calculator

How this calculator works

The total rise is divided into a whole number of near-equal risers; the total run is divided across treads.

Change one assumption at a time to see which inputs have the greatest effect on the estimate.

Worked example

A 105 in rise with a 7 in target gives 15 risers.

Limitations

Building-code requirements and site conditions vary. This is a preliminary geometry estimate, not a construction plan; confirm it with a qualified professional and local authority.

Review this educational estimate against current quotes, official information, and your own budget before making a financial decision.