How do I calculate how much concrete I need?

Multiply length × width × thickness (all in feet, converting inches to feet), then divide by 27 to get cubic yards. Add 10% for waste.

How many bags of concrete per cubic yard?

You need approximately 45 bags of 80 lb concrete mix, or 60 bags of 60 lb mix to make one cubic yard of concrete.

How thick should a concrete driveway be?

Residential driveways should be at least 4 inches thick. For heavier vehicles or trucks, use 5-6 inches with proper rebar or wire mesh reinforcement.

What is the difference between concrete and cement?

Cement is an ingredient in concrete. Concrete is a mixture of cement, sand, gravel, and water. You cannot pour cement alone — it needs the aggregate mix.

How long does concrete take to cure?

Concrete reaches about 70% strength in 7 days and full design strength (28-day strength) in 28 days. You can walk on it after 24-48 hours and drive on it after 7 days.

Concrete Calculator – DIY Calculators — Free Home Improvement Tools

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Quick Answer

To calculate concrete needed, multiply length × width × thickness (all in feet, converting inches by dividing by 12), then divide by 27 to get cubic yards. Add 10% for waste and uneven ground — it is always better to have a little extra than to run short mid-pour.

Calculate concrete volume for slabs, footings, or posts. Get cubic yards and bag count.

Project Type

Length (feet) Width (feet) Thickness (inches)

Bag Size

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Cite This Tool

Concrete Calculator. (2026). DIY Calculators Online. Retrieved from https://diycalculator.net/concrete-calculator/

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