Concrete Calculator
Estimate concrete volume for your slab with a waste allowance and optional cost.
Practical calculatorGeneral editable assumptionsGlobal-readyInteractive chart
Last updated: 2026-05-31
This calculator uses generic assumptions. Use advanced mode to override them for a more accurate result.
Inputs
Formula transparency
Source: defaultV = L × W × D · Total = V × (1 + Waste%)
Frequently asked
- Bags per m³?
- Around 42 × 50 kg bags per m³ for ready-mix.
- Waste %?
- 10% for hand pours/simple shapes. 15% for complex.
- Accurate?
- Volume estimate only. Confirm final quantity with your contractor.
- Rebar?
- No — rebar needs a separate schedule. This is volume only.
- Imperial supported?
- Yes — pick the imperial system and enter feet.
Related calculators
- Unit Converter
Convert between length, weight, temperature, area, and volume units — meters, feet, kilograms, Fahrenheit, liters, and more. Precise and instant.
- Down Payment Calculator
Enter your property or car price and down payment percentage to see the required amount, remaining loan, and the gap between your savings and what's needed.
Results are estimates and not professional advice. Verify important decisions with a qualified professional.