Build & renovate
Stair Calculator
Divide the floor height into equal risers, set the going from the 2R+G comfort rule, and check both against the regulations before cutting a single string.
Fill in the fields above to see results.
How it works
Risers = total rise / preferred riser (rounded to a whole number, then recalculated exactly). Comfort: 2 x riser + going should land between 550-700 mm. UK Part K caps risers at 220 mm (going >= 220); US IRC caps at 7-3/4" (196 mm) with going >= 10" (254 mm).
Frequently asked questions
What is a comfortable stair riser height?
Around 175-190 mm with a 250-280 mm going - that keeps 2R+G near the ideal 630 mm. The maximum legal riser (220 mm UK) is noticeably steep.
How much room does a staircase need?
Total run = going x (risers - 1). A 2.6 m floor height at 185 mm risers is 14 steps - with a 260 mm going that is 3.4 m of horizontal run plus landings.