Stair Calculator
Fill in the values and the answer updates as you type.
How the Stair Calculator works
Number of risers = total rise ÷ preferred riser height, rounded. The exact riser height divides the rise evenly. A common comfort rule says twice the riser plus the tread should be 60 to 66 cm. Local building codes may differ.
Inputs and results
The Stair Calculator takes 3 inputs and gives 4 results.
What you enter
- Total rise (floor to floor) (cm) — starts at 270.
- Preferred riser height (cm) — starts at 17.5.
- Tread depth (cm) — starts at 25.
What you get
- Number of risers
- Exact riser height (cm)
- Total run (m)
- Comfort check (2 × riser + tread)
Example: Stair Calculator with the starting values
With total rise (floor to floor) 270 cm, preferred riser height 17.5 cm and tread depth 25 cm, the calculator returns:
| Number of risers | 15 |
|---|---|
| Exact riser height (cm) | 18 |
| Total run (m) | 3.5 |
| Comfort check (2 × riser + tread) | Comfortable (61.0 cm) |
Change any value above and the results update straight away.
Stair Calculator FAQ
How do I use the Stair Calculator?
Enter total rise (floor to floor), preferred riser height and tread depth in the fields, then read number of risers, exact riser height (cm), total run (m) and comfort check (2 × riser + tread) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Stair Calculator calculate?
Number of steps, exact riser height, and total run for a staircase. It returns number of risers, exact riser height (cm), total run (m) and comfort check (2 × riser + tread) from the 3 values you provide.
What values does the Stair Calculator start with?
It opens with total rise (floor to floor) 270 cm, preferred riser height 17.5 cm and tread depth 25 cm so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Stair Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Stair Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.