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Concrete Stairs Calculator

Estimate concrete volume for a stair flight from rise, run, width, landing, and waist thickness.

Reviewed
2026-09-05
Units
US + metric

Calculated result / live

23 80 lb bags

Order 23 80 lb bags for 13.53 ft³ of concrete including 10% waste.

1 steps at 7.0 in rise × 11.0 in run, 10.00 ft wide, 4.0 in waist, plus landing.

Input panel

Project measurements

Secondary quantities
Stepped profile5.35 ft³
Waist slab3.62 ft³
Landing3.33 ft³
Cubic yards0.50
80 lb bags23

Calculation trace

Formula with your numbers

stepped profile 5.35 + waist 3.62 + landing 3.33 = 12.30 ft³; + 10% = 13.53 ft³

23 80 lb bags
01

What this concrete stairs calculator calculates

Three 7 in rises and 11 in runs produce a stepped profile before the waist and landing are added. Leaving out the waist makes the order too small.

Formula

Stepped profile + sloped waist slab + landing = base volume; multiply by 1 + waste percent and convert to bags.

Worked example

For 3 steps, 7 in rise, 11 in run, 4 ft width, a 4 in waist, and a 1 × 4 ft landing, the model is 18.51 ft³ before waste.

Ordering decision

Stair rise, run, reinforcement, support, and landing geometry must comply with local code and the structural plan.

The page cites the applicable Uzi Tools reference table beside the calculator. Product labels, current editions, local code, and a licensed professional govern structural, electrical, and life-safety work.

02

How to use it

  1. Enter the measured dimensions and keep the displayed units beside each field.
  2. Review the concrete for a stair flight result and the substituted formula before ordering.
  3. Adjust waste for the layout, cut pattern, product package, and site conditions.
  4. Copy or print the material list, then verify the cited product data and local requirements.
03

Concrete for a stair flight

Use this stair calculator to estimate the stepped profile, sloped waist, and landing as separate concrete volumes. Rise, run, step count, width, and waist thickness each change the result.

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Limits and professional review

Measurements, product yield, waste, moisture, and site conditions can change the order quantity. Local code and a licensed professional govern structural and electrical work.

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Data sources

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Related calculations

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Same-project tools

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Questions specific to this estimate