How to use this stair calculator
Enter the values requested above and select Calculate. Change any input to compare another scenario. The calculation runs locally in your browser and does not require an account.
Formula and method
Example
For 108 inches of total rise and a 7.5-inch target, the calculator estimates the number of equal risers.
Tips for a useful result
Stair codes vary by location and project type; use this for preliminary layout only.
What this calculator is useful for
Estimate stair riser count, actual riser height and tread run from total rise and target riser height. The result is intended for quick estimates, checking arithmetic and comparing scenarios. When a result affects a contract, tax filing, medical decision, building-code requirement or other high-stakes situation, verify the result with the appropriate professional or authoritative source.
Frequently asked questions
What does the Stair Calculator calculate?
Estimate stair riser count, actual riser height and tread run from total rise and target riser height.
How does the Stair Calculator work?
Riser count ≈ total rise ÷ target riser height, rounded to a whole number; actual riser height = total rise ÷ riser count.
Is the Stair Calculator free to use?
Yes. ERICH Calculators is free to use and does not require an account.