What is the Stair Calculator?
The stair calculator is a free online tool that helps you work out stair quickly and accurately. It uses the standard formula Steps = round(total rise / ideal riser); riser = total rise / steps and shows the result instantly as you type, along with a full breakdown so you can see exactly how the answer was reached.
How to use this calculator
- Enter the total floor-to-floor height.
- Set the ideal riser and tread.
- See the step layout.
Formula used
Steps = round(total rise / ideal riser); riser = total rise / stepsExplanation of each input
- Total height (rise) (m) โ the total height (rise) used in the calculation.
- Ideal riser height (mm) โ the ideal riser height used in the calculation.
- Tread depth (mm) โ the tread depth used in the calculation.
Understanding your result
- Number of steps โ the calculated number of steps.
- Actual riser height โ the calculated actual riser height in mm.
- Total run โ the calculated total run in m.
Step-by-step calculation
For the example values 3m, 170mm riser:
- Apply the formula:
Steps = round(total rise / ideal riser); riser = total rise / steps - Substitute the values: 3000/170 = about 18
- Result: 18 steps, riser 167 mm
Worked example
| Inputs | 3m, 170mm riser |
|---|---|
| Working | 3000/170 = about 18 |
| Result | 18 steps, riser 167 mm |
Benefits and practical uses
This calculator saves you time and reduces errors when you need stair. It is useful for students, professionals and anyone who wants a fast, reliable answer without manual calculation. Results update instantly, work in your browser and can be copied or shared in one click.
Assumptions and limitations
- Straight flight; building codes vary - verify locally.
Frequently asked questions
What is a comfortable riser height?
Around 150-180 mm per step is comfortable for most people.
Disclaimer: Results are provided for general information. Please verify important figures independently.