Concrete Mix Calculator

What this concrete mix calculator is estimating

Concrete mix planning is different from simply ordering finished concrete by volume. Once you decide to batch concrete on site, you need to turn the target placed volume into a dry-material breakdown that reflects both waste and the way wet concrete yield differs from loose dry ingredients.

That is what this concrete mix ratio calculator is built to do. It starts with the finished target volume, applies waste, expands that to a dry-material requirement with the dry-volume factor, and then splits the dry mix into cement, sand, and aggregate quantities according to the selected ratio.

Core concrete mix formulas

The calculator follows the standard site-batching sequence: adjust the target volume for waste, apply a dry-volume factor, find the total mix parts, then allocate the dry volume across the cement, sand, and aggregate shares. The cement portion is then converted into mass and bag count using the selected bag size.

How to use the mix ratio result

Use the dry mix volume and ingredient split to plan site batching, compare different mix-ratio presets, and check whether your chosen bag size leaves you with a practical order quantity. The cement share is especially useful when deciding whether a richer or leaner mix materially changes the number of bags you need.

For example, a 10 ft³ target concrete volume with 10% waste, a dry factor of 1.54, and a 1:2:4 mix returns about 16.94 ft³ of dry material, of which roughly 2.42 ft³ belongs to cement, 4.84 ft³ to sand, and 9.68 ft³ to aggregate. That breakdown helps you plan batching rather than just the finished pour size.

What this result does not cover

This tool is a batching and estimating aid, not a structural mix-design tool. It does not account for admixtures, aggregate moisture, slump targets, air entrainment, strength-class compliance, or supplier-specific product yield. It also assumes the chosen dry factor and ratio are appropriate for the concrete work you intend to make.

Use it to plan ingredients and compare mix assumptions, then confirm the final mix design and product suitability from the project specification or supplier documentation before you batch or pour.