Construction
Concrete calculator
Calculate rectangular concrete volume with an allowance.
Your numbers
Both a decimal point and a comma work.
Result
3.3 m³
Concrete including allowance
- Net volume
- 3 m³
How it works
V = length × width × depth × (1 + reserve/100)
Using the calculator
Enter: Length · Width · Thickness / depth · Allowance. Calculation: V = length × width × depth × (1 + reserve/100).
Worked input and result
Example: Length = 6 m; Width = 3 m; Thickness / depth = 0.2 m; Allowance = 5 %. Result: Concrete including allowance = 3.78 m³ (Net volume: 3.6 m³).
Understanding the result
Length × width × depth gives m³, then the allowance is added. Enter all dimensions in metres. This material quantity estimate does not determine structural strength or mix design.
Net volume is length × width × depth; the waste percentage is applied afterwards. Use metres consistently, and check whether your supplier rounds orders to whole bags or delivery units.