Start stair checks from total rise
A 2.4 m total rise over 12 steps gives a 0.20 m riser. Changing the step count while keeping the same rise changes the riser height, so the two inputs should be evaluated together.
090 · REAL ESTATE & BUILD
Stair & Ramp Calculator
Enter total height and horizontal run, or step count and tread depth, to calculate sloped length, slope percentage and angle, riser height, and tread depth.
LOCALCALCULATE IN YOUR BROWSER
LOCALDimensions are calculated only in this browser and are not sent to or stored on a server.
STAIR INPUTStairs
RESULT · Result
Total Height2.4 m
Horizontal Run3.36 m
Sloped Length4.129 m
Slope %71.429%
Slope Angle35.538°
Number of Steps12
Riser Height0.2 m
Tread Depth0.28 m
Formula
Riser Height = Total Height ÷ Number of Steps · Slope % = Total Height ÷ Horizontal Run × 100 · Slope Angle = atan(Total Height ÷ Horizontal Run)This is a geometry reference and does not determine compliance with building, accessibility, railing, landing, or structural-safety rules.
Display decimals
3
HOW TO USE
How to use
- 01
Choose Stairs or Ramp.
- 02
Select mm, cm, or m and enter the total height.
- 03
For stairs, enter the number of steps and either tread depth or horizontal run.
- 04
For ramps, use horizontal run, slope percentage, or slope angle as the input basis.
- 05
Review sloped length, slope percentage, slope angle, and stair dimensions together.
- 06
Before construction, verify site dimensions and applicable building and safety requirements separately.
STAIR & RAMP GEOMETRY
Stair and ramp dimension guide
Connect tread depth to horizontal run
Twelve 0.28 m treads give a reference run of 3.36 m. Real stairs can require site checks for top and bottom finishes and how the step count is defined.
Cross-check ramp geometry
A 2 m rise with 4 m run gives 50%, about 26.565°, and about 4.472 m sloped length. These three outputs can be cross-checked from the same rise and run.
Slope percent and angle are different
Slope percent is rise/run×100, while angle is atan(rise/run). For example, a 10% slope is about 5.71°, not 10°.
Work backward from a target slope
For a 1 m rise at 10%, required horizontal run is 1÷0.10=10 m. A gentler target slope requires a longer run for the same rise.
Separate geometry from compliance
This tool calculates geometry. Stair width, landings, rails, headroom, ramp clear width, and applicable legal or site requirements must be checked separately.
IMPORTANT NOTES
Important notes
- Results are geometry references and do not determine legal or accessibility compliance.
- Stair width, landings, railings, headroom, ramp clear width, and structural safety are outside this first release.
- A 10% slope is not the same as a 10° slope angle.
- Lengths are normalized to meters internally and rounded only for display.
- The result does not guarantee constructability or structural safety.
- Displayed values are rounded after calculation, so for follow-up checks use the original dimensions rather than re-entering rounded display values when possible.
FAQ
Frequently asked questions
01What do 2 m rise and 4 m run produce?+
A 50% slope, about 26.565°, and about 4.472 m sloped length.
02What is the riser height for 2.4 m over 12 steps?+
2.4 ÷ 12 = 0.20 m.
03What run do 12 treads at 0.28 m produce?+
0.28 × 12 = 3.36 m.
04What run is required for 1 m rise at 10%?+
1 ÷ 0.10 = 10 m.