Stair Calculator

From the total floor-to-floor rise and your target step height, get the number of risers, the exact riser height, the tread count and total run — with a comfort check on the step ratio.

Staircase

Total rise (floor to floor) mm

Preferred riser height mm

Comfortable range ≈ 150–190 mm. Many codes cap at ~190–220 mm.

Going (tread depth) mm

Often ≥ 250 mm for comfort; check your local code.

Results

Number of risers—

Actual riser height—

Number of treads—

Total run (horizontal)—

Comfort 2R + G—

Risers = round(total rise ÷ preferred riser); actual riser = total rise ÷ risers. Treads = risers − 1. The rule 2 × riser + going ≈ 600–630 mm indicates a comfortable stair. Always verify against the governing building code.