Concrete calculator
Base volume: 2.6500 m³. Includes 10% allowance. Slab estimate only; structural design requires project-specific advice.
Volume = length × width × (depth in mm ÷ 1,000)
Formula
Length × width × depth in meters
How the calculation works
Estimate slab volume with an adjustable waste allowance. Enter each measurement in the unit shown beside the input. The result updates when you change a value; incomplete or unsupported inputs display an explanation.
Worked example
5 m × 4 m × 0.1325 m = 2.65 m³; with 10% allowance, order volume is 2.915 m³.
When to use this calculator
Use this for rectangular slab quantity estimates.
Common mistakes and limits
Enter depth in millimeters. This estimates volume, not strength, reinforcement, foundation design, or bag yield.
Check your result
Check that all measurements describe the same object or time period. Repeat the calculation with unrounded values, then round only the final quantity to a precision suitable for the task.
Frequently asked questions
Does this calculator need an account?
No. Calculations run in your browser without an account.
How precise is the displayed result?
The display rounds to six decimal places. Measurement uncertainty can be larger than this rounding.
