Concrete Calculator

How to Use This Calculator

Ordering the right amount of concrete prevents waste and costly delays. Here's how to calculate exactly what you need:

1. Select your project type - slab (patios, driveways), footing (foundation walls), column (posts, piers), or stairs.
2. Enter the dimensions in feet and inches. For slabs, you'll need length, width, and thickness. Other shapes have specific measurements.
3. Adjust the waste factor if needed - 10% is standard, but complex forms or remote pours may need more.
4. Optionally enter your local concrete price per cubic yard to estimate total material cost.
5. Click 'Calculate' to see cubic yards needed, including the waste allowance.

Why This Matters

Concrete is sold by the cubic yard, and getting the quantity wrong is expensive either way. Order too little and you'll have an incomplete pour, cold joints, and potentially need to tear out and start over. Order too much and you're paying for material you can't use - concrete trucks charge for full loads regardless of what you pour. Most suppliers require a minimum order of 1 cubic yard, and short-load fees apply for less than full trucks (typically 8-10 yards).

• Avoid costly short pours that compromise structural integrity
• Prevent over-ordering and paying for unused material
• Account for waste from spillage, uneven subgrade, and form overflow
• Plan accurate budgets with material cost estimates
• Calculate complex shapes like stairs and columns with confidence

Worked Examples

Common Mistakes to Avoid

• Measuring in inches but forgetting to convert to feet - always double-check your units.
• Forgetting that thickness is part of the volume - a 4-inch slab uses much less concrete than a 6-inch slab.
• Not accounting for waste - forms leak, subgrade is uneven, and you'll always lose some to the mixer.
• Ordering exactly the calculated amount with no buffer - always round up to avoid a short pour.
• Not checking minimum order requirements - most suppliers won't deliver less than 1 cubic yard.