Driveway & patio tool

Calculate concrete for a driveway or patio.

Enter the length, width, and thickness of your driveway or patio to estimate the concrete order quantity, including waste allowance.

No sign-up Formula shown Print-ready
Step 1

What are you pouring?

More shapes
Measure this shape Slab or patio

For patios, driveways, walkways, shed pads, and other rectangular pours.

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 thick should a concrete driveway be?

Most residential driveways use 4 to 6 inches of concrete. Heavier vehicle loads or poor soil may require thicker sections. Check local building codes for specific requirements.

How much concrete for a 20x20 driveway?

A 20×20 driveway at 4 inches thick needs about 0.49 cubic yards. At 6 inches thick, it requires about 0.74 cubic yards. Add 5–10% for waste.

How much does a concrete driveway cost?

Cost depends on thickness, total area, and local material prices. Enter your dimensions and price per yard or bag above to get an estimate.

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.