Concrete Calculators

Working with concrete & masonry quantities

Concrete is unforgiving about quantity in a way most materials are not. Running short mid-pour creates a cold joint — a plane where fresh concrete meets partly set concrete and never fully bonds — which is a permanent weakness you cannot repair afterwards. Every calculator here adds a 10% allowance for that reason.

Worth knowing: Ready-mix beats bags past about one cubic yard. Below that, short-load fees of $100 to $200 usually make bags the cheaper option despite the mixing.

These 9 calculators cover about 34,310 searches a month between them. Every one prints the formula it uses and a worked example, so you can check the result by hand before you order.