Concrete Calculator
Estimate concrete volume
Quick guide
What can Concrete Calculator help you do?
Free concrete calculator for cubic meters, cubic yards, and 40kg bags. Bag count explicitly assumes a yield of 0.017 m³ per bag.
Best for
Estimate a rectangular pour from its length, width, and depth, with volume and an indicative bag count. It is a material-volume calculation, not a structural design tool. Irregular shapes, voids, reinforcement, slopes, and load capacity require separate assessment.
How to use it
Enter all three dimensions in metres; a 12-centimetre slab depth is 0.12, not 12. Calculate to see cubic metres, cubic yards, and 40 kg bags. The example dimensions 4 by 3 by 0.12 metres produce 1.44 cubic metres.
How to read the result
The bag count assumes each 40 kg bag yields 0.017 cubic metres and rounds up. Under that assumption, 1.44 cubic metres requires 85 bags. Actual packaged-product yield can differ, so bag weight alone does not establish the correct count.
Privacy and limits
Only typed dimensions are used; no site address, drawing, or project document is uploaded for this calculation. You can label areas in your own records and share dimensions without exposing a full building plan or private project information.
The result excludes waste and contingency and is not structural advice. Check the product's stated yield and have a qualified contractor or engineer confirm materials, strength, and site requirements before ordering or carrying out load-bearing work.
Frequently Asked Questions
What units should I enter?
Enter length, width, and depth in meters.
How is bag count estimated?
The tool assumes 0.017 m³ yield per 40kg bag. Actual yield varies by product, so use its datasheet and add job-site waste.