Calculate a Staircase: Rise, Run & Riser
A free stair calculator for planning a staircase. Enter the total floor-to-floor rise, the number of steps and the tread depth, and it works out the exact riser height, total run, stair angle and stringer length — and checks them against common building-code comfort ranges.
How to calculate a staircase
1
Measure the total rise
Measure the vertical height from the lower finished floor to the upper finished floor and enter it.
2
Set the number of steps
Use the + and − buttons to land on a comfortable riser height — the result updates instantly.
3
Set the tread depth
Enter the depth of each step. The tool shows the run, angle, stringer length and code checks.
Plan stairs with safe riser, tread and angle
The vertical height from the lower finished floor to the upper finished floor.
mm
Total steps including the top one. Adjust to land on a comfortable riser height.
The horizontal depth of each step you walk on.
mm
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Riser height
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Tread depth
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Stair angle
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Total run
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Stringer length
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Steps / treads
Published
Updated
