Staircase calculator
Risers, treads, going, pitch and comfort check from floor-to-floor height.
How it is calculated
Number of risers = floor-to-floor height ÷ maximum riser, rounded up. Riser = height ÷ number of risers. A straight flight has one tread fewer than risers. Total going = treads × tread depth. Pitch = arctan(riser ÷ tread). Comfort (Blondel): 2 × riser + tread should be between 550 and 700 mm (about 22–27½ in).
Check locally: Maximum riser, minimum tread, pitch, headroom and handrail rules differ by country and building type. Check the code that applies to your project.
Questions
What is the 2R + T rule?
Twice the riser plus the tread (going) should be between about 550 and 700 mm for a comfortable stair. It is a guide, not a code requirement.
Does it check building codes?
No. It shows the geometry. Maximum riser, minimum tread and headroom rules depend on your country and building type.
Is anything I enter saved or sent?
No. The calculation runs in your browser. Nothing you type is sent anywhere. You can copy the result, print it or download it as a CSV.