Stair Step Calculator
The number of steps must be a whole number, so it is rounded up and the total rise divided again for the actual riser. Every riser must match, or people trip.
Your numbers
Steps
16
Riser height
17.5cm
Grade (%)
67.3%
What it means
2 × riser + tread = 61 cm, inside the comfortable 60–65 cm range.
Formula
Steps = ⌈Height ÷ Riser height⌉
The long-standing rule for comfortable stairs is 2 × riser + tread = 60–65 cm.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Height (cm)The perpendicular height from the base — not the slanted side. | 280 | 1 and up |
| Riser height (cm)The rise of a single stair. | 18 | 5 ~ 30 |
| Run (cm)How far it travels horizontally. | 26 | 15 ~ 40 |
Step by step
Quick reference table
Results when only Height (cm) changes and everything else stays put.
| Height (cm) | Steps | Riser height (cm) | Grade (%) (%) |
|---|---|---|---|
| 140 | 8 | 17.5 | 67.3 |
| 210 | 12 | 17.5 | 67.3 |
| 280 | 16 | 17.5 | 67.3 |
| 420 | 24 | 17.5 | 67.3 |
| 560 | 32 | 17.5 | 67.3 |
What each result means
| Result | At default values |
|---|---|
| StepsHow many stairs there are; times the rise gives the total climb. | 16 |
| Riser height (cm)The rise of a single stair. | 17.5 |
| Grade (%) (%)How far you rise over 100 of horizontal run. | 67.3 |
Common mistakes
The long-standing rule for comfortable stairs is 2 × riser + tread = 60–65 cm.
Glossary
- Height
- The perpendicular height from the base — not the slanted side.
- Riser height
- The rise of a single stair.
- Run
- How far it travels horizontally.
- Steps
- How many stairs there are; times the rise gives the total climb.
- Grade (%)
- How far you rise over 100 of horizontal run.
Frequently asked questions
Q. How is Stair Step Calculator calculated?
Steps = ⌈Height ÷ Riser height⌉ — The number of steps must be a whole number, so it is rounded up and the total rise divided again for the actual riser. Every riser must match, or people trip.
Q. Can you walk through an example?
With Height 280cm, Riser height 18cm, Run 26cm, the answer is Steps 16.
Q. What do I need to enter?
Enter Height, Riser height, Run. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Height (cm) moves the answer to Height (cm) 140 → Steps 8 and Height (cm) 560 → Steps 32. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
The long-standing rule for comfortable stairs is 2 × riser + tread = 60–65 cm.
Related calculators
Keep your length units consistent across inputs — mixing centimetres and metres throws results far off.