Back to Construction & DIY

How to Use Our Concrete Calculator

3 min read

How to Use Our Concrete Calculator

Getting concrete quantities wrong means either running out mid-pour or paying for excess. Our Concrete Calculator ensures you order the right amount every time.

Entering Your Project Dimensions

  • Length -- The length of your pour area in feet or meters.
  • Width -- The width of your pour area.
  • Depth (Thickness) -- The thickness of the concrete slab. Standard sidewalks use 4 inches, driveways use 4-6 inches, and structural foundations use 6-12 inches.

For non-rectangular areas, divide the project into rectangular sections and calculate each separately.

Understanding Your Results

Cubic Yards -- The standard ordering unit for ready-mix concrete trucks. One cubic yard covers about 80 square feet at 4 inches thick.

Cubic Feet -- Useful for smaller projects where you are mixing by hand.

Number of Bags -- The calculator converts to common bag sizes (40 lb, 60 lb, or 80 lb bags). An 80-lb bag of premixed concrete yields about 0.6 cubic feet.

Always Order Extra

Add 10% to your calculated amount for waste, uneven surfaces, and spillage. For projects with many forms, corners, or irregular shapes, add 15%. Running out of concrete during a pour is far worse than having a little left over.

Related Calculators