Stair Rise & Run Calculator

Free stair calculator. Enter total rise height to find the number of steps, riser height, and tread depth that meet building code requirements. Use our free cal

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Number of Steps hesaplanacak
Actual Riser Height hesaplanacak
Stringer Length hesaplanacak
Total Horizontal Run hesaplanacak

Stair Design Fundamentals

A safe and comfortable staircase requires careful calculation of three key dimensions: rise (vertical height of each step), run (horizontal depth of each tread), and the total number of steps. Building codes specify acceptable ranges for safety.

Key Stair Dimensions

  • Total Rise: Vertical distance from floor to floor
  • Riser Height: Height of each individual step (typically 150–200 mm)
  • Tread Depth: Horizontal depth of each step (typically 250–300 mm)
  • Number of Steps: Total Rise / Riser Height (round to nearest whole number)

Building Code Guidelines (Most Jurisdictions)

DimensionResidentialCommercial
Maximum riser height220 mm180 mm
Minimum tread depth220 mm280 mm
Minimum stair width860 mm1,000 mm
Handrail height900–1,000 mm1,000 mm

The Comfort Formula

A well-designed staircase follows: 2 x Rise + Run = 600–650 mm
Example: 175 mm riser + 300 mm tread = (2 x 175) + 300 = 650 mm — perfect comfort.

Example Calculation

Floor-to-floor height: 2,800 mm
Target riser: 175 mm
Number of steps: 2,800 / 175 = 16 steps
Actual riser: 2,800 / 16 = 175 mm exactly
Tread (for comfort): 650 - (2 x 175) = 300 mm

How to Use This Calculator

Using our calculator is simple: enter the required values into the input fields and click the calculate button. Results are displayed instantly on screen. You can adjust the values and recalculate to compare different scenarios and find the best option for your situation.

Frequently Asked Questions

QuestionAnswer
How accurate are the results?We use standard formulas and up-to-date 2025 rates. Individual circumstances may vary slightly.
Is this calculator free?Yes, completely free and no registration required.
What should I do for exact figures?For precise information, consult a relevant professional or official authority.
Does it work on mobile devices?Yes, it works seamlessly on all devices and screen sizes.

Important Notes

This calculator is provided for informational purposes only. For legal, financial, or medical decisions, always seek advice from qualified professionals. Calculation results do not constitute official documents. Legislative changes may affect results; please visit the relevant official website for the most up-to-date information. Our calculators are regularly updated to reflect current regulations and rates.

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Frequently Asked Questions

The "comfort rule" is 2 × riser + tread = 60-65 cm. A riser of 18 cm + tread of 27 cm gives 63 — ideal. Most building codes require riser 15-22 cm, tread 22-32 cm.
Divide total height by desired riser height, then round up to the nearest whole number. The actual riser is then total height divided by the number of steps.
The stringer (or carriage) is the diagonal support beam that the stair treads rest on. Its length is calculated using the Pythagorean theorem: √(rise² + run²).