Stairs planning tool

Calculate concrete for stairs.

Enter the width, run, rise, and number of steps to estimate the concrete volume for your stair project.

No sign-up Formula shown Print-ready
Step 1

What are you pouring?

More shapes
Measure this shape Stairs

Estimate a standard stepped form or a solid ramp fill, including an optional top platform.

Diagram not to scale
Step 2

Enter your measurements

Step 3

Add a waste allowance

The suggested allowance reflects the selected project shape.

Your estimate

Purchase summary

A reliable estimate in four steps

Measure once. See the math. Buy with confidence.

  1. 1
    Choose the project shape

    Select the geometry that matches the concrete you are pouring.

  2. 2
    Enter measured dimensions

    Use US or metric units and adjust individual fields when needed.

  3. 3
    Review the waste allowance

    Use the project suggestion or enter a value that matches site conditions.

  4. 4
    Compare purchase options

    Use the recommended bag count or ready-mix quote quantity as a starting point.

Planning guidance

Common concrete estimate questions.

How do I calculate concrete for stairs?

Enter the total width, horizontal run, vertical rise, and number of steps. The calculator computes the volume for both standard stepped and solid ramp styles.

How much concrete for exterior stairs?

It depends on the number of steps and dimensions. A typical 4-step exterior stair at 36 inches wide needs about 0.3 cubic yards. Use the calculator above for your exact measurements.

How much extra concrete should I order?

A 5–10% allowance is common for regular forms. Uneven excavation, stairs, or uncertain measurements may justify 10–15%. The calculator suggests a starting point that you can change.

Should I use bags or ready-mix concrete?

Bagged concrete is often practical below 0.5 cubic yard. Between 0.5 and 1 cubic yard, compare mixing labor with local short-load fees. Above 1 cubic yard, start with a ready-mix quote.