Archi Conquer · Free practical tool

Stair geometry calculator

Test a chosen integer riser count against floor-to-floor height. Explain why a straight flight with the upper floor as its final tread has one fewer going than risers.

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The method

Riser height = floor height/riser count; straight-flight going = (riser count−1) × tread.

Before using the result

  • Single straight flight with the upper floor serving as the final tread. Landings, nosings, headroom and regulatory limits are not modelled.

Worked examples

These original training examples illustrate the method for Architect Registration Examination (ARE) - United States. Use the matching “Load example” button above to explore a variation; example values are not equipment settings or prescribed criteria.

1. Worked example

Test a chosen integer riser count against floor-to-floor height. Explain why a straight flight with the upper floor as its final tread has one fewer going than risers.

Floor-to-floor height
3 m
Chosen riser count
18
Tread depth
0.28 m
  1. Riser = 3 / 18 m.
  2. Going = (18 − 1) × 0.28 m.
  • Riser height: 0.1666667 m
  • Tread count: 17
  • Straight-flight going: 4.76 m

2. Comparison example

Compare a different supplied condition using the same method. For Archi Conquer, the important check is that the input meaning, units and method assumptions still match the problem.

Floor-to-floor height
3 m
Chosen riser count
20
Tread depth
0.28 m
  1. Riser = 3 / 20 m.
  2. Going = (20 − 1) × 0.28 m.
  • Riser height: 0.15 m
  • Tread count: 19
  • Straight-flight going: 5.32 m

Check your understanding

1. Which relationship is used?

Riser height = floor height/riser count; straight-flight going = (riser count−1) × tread.

2. Which assumption should you check first?

Single straight flight with the upper floor serving as the final tread. Landings, nosings, headroom and regulatory limits are not modelled.

3. How should you verify a different unit system?

Convert every input to the displayed calculation units first. Equivalent physical inputs must give equivalent results; a unit label alone does not convert a number.

Continue with the matching exam topic

This tool connects to Architect Registration Examination (ARE) - United States free practice. Work through a question independently, then use the calculation steps to identify where your method differs. The tool stays free whether or not you choose paid preparation.

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