Plan safer stairs fast with accurate risers, treads, and slope checks today. Adjust units, limits, and rounding to match your project requirements exactly easily.
| Total rise | Target riser | Tread depth | Computed risers | Riser height | Total run | Angle |
|---|---|---|---|---|---|---|
| 2800 mm | 175 mm | 250 mm | 16 | 175.0 mm | 3750 mm | 36.7° |
| 3000 mm | 180 mm | 270 mm | 17 | 176.5 mm | 4320 mm | 34.8° |
| 108 in | 7 in | 10 in | 15 | 7.2 in | 140 in | 37.7° |
Example values are illustrative and may not match local requirements.
Accurate riser design reduces falls and improves flow in homes, shops, and public corridors for most residential and light commercial staircases. A practical target is about 150–190 mm or 6–7.5 in, while keeping every riser uniform. This tool converts your floor rise into a realistic riser count and checks the final height against your chosen limits.
Total rise is the finished floor-to-floor vertical distance, including finishes such as tile, screed, or timber. The target riser guides the best-fit search, while minimum and maximum riser settings bound the solution. Add tread depth to estimate required space, and include nosing if you want an effective going for foot placement.
The core step is selecting N, the number of risers. The calculator tests feasible N values where R = Rise ÷ N stays between your minimum and maximum. “Best fit” picks the N that makes R closest to your target, while ceil, floor, and round let you bias the result for comfort or space.
For a straight flight, tread count is typically N − 1 because the upper floor acts as the final landing surface. Total run equals tread count × tread depth, so small changes in tread depth can shift space needs quickly. Example: 16 risers with 250 mm treads uses 15 × 250 = 3750 mm of run.
Pitch angle uses arctan(Rise ÷ Run). Many comfortable stairs land around 30°–40°, but projects vary. Stringer length is √(Rise² + Run²), useful for material planning and cutting allowances. Compare options by adjusting tread depth or rounding mode, then reviewing angle and stringer length together.
A common walking-rhythm indicator is 2R + T, where R is riser height and T is tread depth. Typical bands are roughly 600–650 mm or 24–25 in, but you can set your own range. If the value is high, stairs feel steep; if low, they feel long and shallow.
Codes often limit maximum riser height and minimum tread depth, and many also restrict variation between steps. Enter project-specific limits so warnings highlight potential noncompliance early. Treat warnings as design flags, not approvals, and confirm requirements with local standards before fabrication or inspection.
Before cutting stringers, remeasure rise after finishes are installed or thicknesses are confirmed, because a 10–20 mm change can alter riser count. Save the CSV for project records and the PDF for reviews. Consistent layout marks, landing allowances, and on-site checks help deliver safer, repeatable stair geometry.
On a straight run, the top floor acts like the final tread surface. That means if you have N risers, you typically have N−1 tread boards. Some designs differ with landings.
Use the riser count and riser height output as a starting point. Then split the stair into runs separated by landings, distributing treads and space constraints across each run.
Start near the middle of your acceptable range, then check total run and pitch. If space is limited, a slightly higher riser may help. If comfort is priority, lower risers can help.
It indicates step rhythm. If the value is low, the stair can feel flat and long. If the value is high, it can feel steep. Use it alongside pitch and code checks.
Warnings depend on the limit settings you entered. If your project follows different standards, adjust the code maximum riser, minimum tread, or comfort range to reflect your requirements.
Yes. Measure from finished floor to finished floor whenever possible. If finishes are not installed yet, estimate thickness and verify again before final cutting and installation.
You can estimate risers and run, but exterior stairs often require additional considerations like drainage, slip resistance, and different code limits. Always validate with the applicable outdoor requirements.
Measure carefully, verify codes, and build stairs confidently always.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.