Equal Riser Stair Layout Calculator
Divide a total rise into equal risers and list tread elevations and horizontal positions from entered dimensions.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Use an entered count or round total rise divided by your maximum riser height upward. Divide rise equally and use one fewer intermediate tread than risers before the upper landing.
Actual riser=total rise/N; intermediate treads=N−1; horizontal run=(N−1)×going
Worked example
A total rise of 2800 mm with entered maximum riser 180 mm needs 16 risers at 175 mm. With 270 mm going, 15 intermediate treads give 4050 mm run.
Assumptions and input details
Pure layout geometry. Enter your own dimensions; no jurisdictional stair limits or recommended proportions are supplied. Upper floor is the final landing, with N−1 intermediate treads. Excludes nosing, landings between flights, headroom, structure and code compliance. Maximum 1000 risers; long tables disclose omitted positions.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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