Structure calculator

Stair Rise & Run Calculator

Explore a clear stair layout from total rise and available run. Switch between US customary and metric units, adjust the assumptions, and keep every step visible.

01 Measure02 Allow03 Order

Project inputs

Use one unit system throughout. Defaults show a realistic example; replace them with measurements from your project.

Unit system

Total riseExample input — replace with your project value.inTarget riser heightPlanning default — verify the selected product or project specification.inTread depthPlanning default — verify the selected product or project specification.inStair widthExample input — replace with your project value.in

Measurement guideTotal rise is floor-to-floor height; run is the horizontal tread direction.

Measure the finished shape. Stair geometry is regulated and safety-critical. Treat this as layout exploration only and verify every dimension, landing, headroom, handrail, and guard requirement locally.

Estimate matches the inputs shown.

ReviewedNovember 2, 2026

ByBuildGauge Editorial Team

ScopeFormula, defaults & sources

Report an issue ↗

The calculation

A visible formula, not a black box.

Steps & geometry · Mathematical derivationrisers = nearest whole number to total rise ÷ target riser; actual riser = total rise ÷ risers

Inputs are converted to a common base unit before calculation. Purchase quantities are rounded only at the final buying boundary.

Example inputDefaultStatus

Total rise108 inPlanning default — verify

Target riser height7.25 inPlanning default — verify

Tread depth10.5 inPlanning default — verify

Stair width36 inReplace with measurement

Worked example

Example: a 108 in total rise

A 7.25 in target selects 15 equal risers; verify every resulting dimension against the adopted local code.

Use this to understand the workflow—not as a recommendation for your project.

Sources & scope

What supports this calculation.

Industry guidance2021 International Residential Code R311.7.5 ↗

One US model-code reference only; users must verify the currently adopted local code and complete stair design.

Mathematical derivationNIST SI conversion factors ↗

Exact length, area, and volume unit conversions; the project formula is derived from standard geometry.

Common mistakes

Check the job, not just the number.

01Leaving the example stair rise & run inputs unchanged instead of entering measured project values.
02Treating an editable coverage, size, density, or allowance as universal instead of checking the selected product label, project documents, and local requirements.
03Ordering from the rounded result without reviewing exclusions: Stair geometry is regulated and safety-critical. Treat this as layout exploration only and verify every dimension, landing, headroom, handrail, and guard requirement locally.

Questions, answered

Stair rise & run FAQ

What does the Stair Rise & Run Calculator estimate?

Explore a clear stair layout from total rise and available run. The primary output is steps & geometry, with the intermediate assumptions kept visible.

How is the stair rise & run result calculated?

The visible formula is: risers = nearest whole number to total rise ÷ target riser; actual riser = total rise ÷ risers. Inputs are converted to a common base unit before the final purchase boundary is rounded.

Are the default values recommendations?

No. Dimensions are worked examples and product-dependent presets are planning defaults. Replace them with the selected product label, project documents, and local requirements.

Is the result ready to order from?

Use it as a checked planning estimate, then confirm packaging, minimum orders, installation instructions, site conditions, and any code or professional-design requirements.