Stairs Calculator — Riser, Going & Stringer
Enter the floor-to-floor rise, the number of risers and the tread going to get the riser height, total run, stringer length, pitch angle and a comfort check.
mm
mm
Passes the 2R+G comfort rule (550–700 mm)
- 1
Number of treads
15 − 1 = 14 - 2
Total going (run)
14 × 250 = 3500 mm - 3
Stringer length
√(2700² + 3500²) = 4420 mm - 4
Riser height
2700 ÷ 15 = 180
Kako deluje ta kalkulator?
Divide the total floor-to-floor rise by the number of risers to get the equal riser height. Multiply (risers − 1) by the tread going for total run; the stringer is the hypotenuse. Check that 2 × riser + going falls in the 550–700 mm comfort zone.
Formula
How this is calculated
The calculator divides the total vertical rise (floor-to-floor height) by the chosen number of risers to find the equal riser height. Risers must all be equal — unequal risers are a trip hazard and a building-regulation failure. A staircase with n risers has n − 1 treads, because the top riser brings you level with the upper floor which itself acts as the final landing; the total going is therefore (n − 1) × tread going, and the stringer length is the hypotenuse of the right triangle formed by total rise and total going.
Comfort is checked with the 2R + G rule: twice the riser height plus the going should fall in the 550–700 mm range (ideally near 600 mm). A value below 550 mm means the stair is shallow and tends to feel awkward; above 700 mm it becomes steep. Many national codes (BS 5395 in the UK, DIN 18065 in Germany) formalise similar rules. Residential buildings commonly allow risers of 150–220 mm and goings of 220–300 mm.
All inputs and results are in millimetres. To use centimetres, multiply each mm result by 0.1; to use inches, multiply by 0.03937. The handrail height (900–1000 mm above the nosing, shown for reference) varies slightly by jurisdiction and should be verified against local codes. This calculator assumes a straight staircase; spiral or winder stairs require a different calculation.
Pogosta vprašanja
Each riser raises you to the level of the next tread. The last riser brings you to the upper floor itself, which serves as the final landing — so a flight with n risers only needs n − 1 separate tread boards.
It is a comfort formula: twice the riser height plus the going (tread depth) should total roughly 550–700 mm (ideally around 600 mm). This balance ensures the stair is neither too steep nor too shallow for a natural walking stride.
All results are in millimetres. Divide by 25.4 to get inches. For example, a 175 mm riser is 175 ÷ 25.4 ≈ 6.9 in, and a 250 mm going is about 9.8 in.
TG we-Calculate Editorial Team. (2026). Stairs Calculator — Riser, Going & Stringer [Online calculator]. TG we-Calculate. https://we-calculate.com/sl/calculator/stairs-calculator
TG we-Calculate Editorial Team. "Stairs Calculator — Riser, Going & Stringer." TG we-Calculate. 2026. https://we-calculate.com/sl/calculator/stairs-calculator.
TG we-Calculate Editorial Team, "Stairs Calculator — Riser, Going & Stringer," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/sl/calculator/stairs-calculator
@misc{wecalculate_stairs_calculator, title = {Stairs Calculator — Riser, Going & Stringer}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/sl/calculator/stairs-calculator}}, year = {2026}, note = {TG we-Calculate} }
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