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Concrete Weight Calculator.

Calculate concrete volume and mass from dimensions, an entered density, and an optional waste allowance.

On-device calculationNo signup
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Set your values

Results update as you type.

Results update automatically after a short debounce. Every dimension, material factor, and allowance is entered explicitly; this page does not size structural members or select a product, code, alloy, mix, or schedule.

Use Cases

Estimating concrete for a slab

Determine the volume and weight of concrete needed for a patio, driveway, or foundation slab by entering its dimensions and density.

Example: A 10 ft x 12 ft slab, 4 inches thick, with 5% waste.

Planning concrete delivery

Calculate the total weight of concrete to ensure your site can support the load and to coordinate delivery logistics.

Example: A 20 m x 5 m footing, 0.3 m thick, with 10% waste.

Frequently Asked Questions

How does the Concrete Weight Calculator work?
Enter the length, width, and thickness of your concrete element in your preferred units. The calculator computes the volume, then multiplies by the concrete density (default 2400 kg/m³) to get the mass. You can also add a waste percentage to account for spillage or overage.
What is the default concrete density?
The default density is 2400 kg/m³, which is typical for standard concrete. You can adjust this value based on your specific mix or aggregate type.
Why should I include a waste allowance?
Adding a waste percentage (e.g., 5-10%) accounts for material lost during mixing, transporting, or placing. This ensures you order enough concrete to complete the job without running short.

Tips & Common Mistakes

Tips

  • Measure dimensions accurately in the same units to avoid calculation errors.
  • Use a waste allowance of 5-10% for typical projects; increase for complex shapes or uneven surfaces.
  • Adjust the density if you are using lightweight or heavyweight concrete mixes.
  • Double-check your unit conversions (e.g., inches to feet) before entering values.

Common Mistakes to Avoid

  • Forgetting to convert all dimensions to the same unit before calculating.
  • Using the default density without considering the actual mix design.
  • Omitting the waste allowance, leading to underestimating the required concrete.

Last updated: August 13, 2026