🏠 Home & DIY

Stair Calculator

Calculate the number of steps, riser height and run for a staircase.

in
in
in

Results

Number of risers
15
Actual riser height
7.200 in
Total run
140.0 in
Stair angle
35.8°

📊 Stair Calculator chart

How the number of risers changes as the target riser height varies. The orange dot marks your current value.

What is the Stair Calculator?

Calculate the number of steps, riser height and run for a staircase. Order the right amount the first time. These construction and DIY calculators estimate materials for common home projects and include sensible waste allowances.

Stair Calculator – free online home & diy tool illustration
Stair Calculator — free, exact and private.

How to use the Stair Calculator

  1. Enter your total rise, your target riser height, your tread depth.
  2. Results update automatically as you type; you can also press Calculate.
  3. Read the output: number of risers, actual riser height, total run, stair angle.
  4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Risers = Total rise ÷ target riser (rounded up)

Worked example

With total rise = 108 in, target riser height = 7.5 in, tread depth = 10 in, the Stair Calculator returns number of risers: 15; actual riser height: 7.200 in; total run: 140.0 in.

Tips for better results

  • Add 5–15% for waste, cuts and breakage depending on the material.
  • Measure twice and round up when buying — returns are easier than second trips.
  • Coverage figures vary by product, so check the label or spec sheet.

⚠️ Material estimates are approximate. Follow local building codes and manufacturer instructions.

Frequently asked questions

What does the Stair Calculator do?

Calculate the number of steps, riser height and run for a staircase.

How is it calculated?

The Stair Calculator uses this method: Risers = Total rise ÷ target riser (rounded up).

Can you show an example?

With total rise = 108 in, target riser height = 7.5 in, tread depth = 10 in, the Stair Calculator returns number of risers: 15; actual riser height: 7.200 in; total run: 140.0 in.

Is the Stair Calculator accurate?

It uses standard published formulas and is tested against known values, but results are estimates for guidance. Material estimates are approximate. Follow local building codes and manufacturer instructions.

Is this tool free and private?

Yes — the Stair Calculator is completely free with no sign-up, and it runs entirely in your browser, so the values you enter are never uploaded to our servers.

Related tools

Cubic Yard CalculatorConvert dimensions in feet into cubic yards for dirt, sand, concrete or mulch.Aquarium Volume CalculatorCalculate the water volume of a rectangular fish tank.Pool Volume CalculatorCalculate how many gallons a rectangular pool holds.Concrete CalculatorCalculate the concrete needed for a slab in cubic yards, cubic meters and premix bags.Paint CalculatorEstimate how many gallons of paint you need for a room.Tile CalculatorCalculate how many tiles you need for a floor or wall, with waste allowance.Flooring CalculatorEstimate square footage and boxes of flooring (laminate, vinyl, hardwood).Square Footage CalculatorCalculate square feet of a room or space, plus square meters and cost.

📬 Get new tools first — free

Join Taurang to hear about new calculators, converters and features. No spam; unsubscribe anytime.

Create free account