Concrete Calculator

How to use the Concrete Calculator

1. Choose the shape — slab, footing, column, or steps.
2. Enter your dimensions in metres or feet (length, width, depth).
3. Adjust the waste percentage to account for spillage and over-ordering.
4. Read the total volume in cubic metres and the recommended cement, sand, and aggregate quantities.
5. Use the hand-mix breakdown if you are mixing on site, or the total cubic metres figure when ordering from a ready-mix supplier.

Why use this tool

• Prevents under-ordering, which causes costly delays waiting for a second delivery.
• Calculates both ready-mix volume and hand-mix bag quantities for smaller jobs.
• Supports multiple shape types in a single session so you can total up an entire project.
• Includes a waste adjustment so you can factor in realistic site losses without mental arithmetic.

This tool estimates geometric volume and an order allowance. It does not specify concrete strength class, exposure class, cement type, reinforcement, cover, slump, curing, joints or placement method. Structural and durability requirements must come from the project design, and the exact mix and delivery constraints must be confirmed with the supplier before the pour.

Part of Builder Tools Calculators — free construction tools for UK tradespeople.