Calculator inputs
Estimate cubic metres of concrete for a rectangular slab.
Enter the measurement using the unit shown in the label and keep units consistent.
Enter the measurement using the unit shown in the label and keep units consistent.
Enter the measurement using the unit shown in the label and keep units consistent.
Formula
A 5 m by 3.2 m slab at 0.12 m depth needs 1.92 cubic metres of concrete.
How to use it
Estimate cubic metres of concrete for a rectangular slab. This page keeps the steps simple, shows the core formula, and links to closely related tools so users can keep comparing scenarios.
Concrete ordering tips
Concrete calculations are volume estimates, so the result depends on accurate measurements for length, width, and depth. Always measure in the same unit system and double-check the depth, because small depth errors can noticeably change the total volume.
For real projects, many people add a small allowance for waste, uneven ground, formwork variation, and spillage. The right allowance depends on the project size and site conditions, but it is usually better to slightly overestimate than to run short during a pour.
Before ordering concrete
- Measure the area in multiple places if the ground is uneven.
- Confirm the required slab depth for the project type.
- Check whether the supplier sells by cubic metres, cubic yards, or bags.
- Use the Square Footage Calculator for area checks.
Concrete Calculator FAQ
What does this calculator estimate?
Estimate cubic metres of concrete for a rectangular slab.
How should I read the result?
The result is a quick planning estimate based on the formula shown above.
Where should I go next?
Use the related links to compare adjacent calculators or open the category hub.
Before you order concrete
Measure length, width, and depth carefully and keep all units consistent. For slabs, paths, and footings, adding a small allowance for waste or uneven ground can prevent under-ordering.
Before relying on the result: Concrete requirements can vary with site conditions, reinforcement, compaction, sub-base preparation, and local building requirements.
Accuracy and use of results
CalculatorWorks aims to make calculations clear and practical. We use standard calculation methods where possible, explain assumptions in plain language, and encourage users to verify important results before relying on them.