Concrete Calculators for Contractors

Most concrete estimating starts the same way: how many yards? MudHub's concrete calculators cover the shapes you actually pour, use the units on your plans, and keep the math consistent across the crew so the office and the field order the same amount.

Open a specific tool: slab calculator · footing calculator · wall calculator · column and pier calculator · circular slab calculator · concrete bag calculator · concrete cost estimator · unit converter.

Concrete is ordered by the cubic yard. One cubic yard is 27 cubic feet. To get yards, multiply length × width × thickness in feet, then divide by 27.

Thickness is the number that trips people up, because it is usually measured in inches. Divide inches by 12 before you multiply: 4 inches is 0.333 ft, 6 inches is 0.5 ft. Going from 4 to 5 inches adds 25 percent more concrete to the same slab, so enter the thickness you will actually pour.

The calculators give theoretical volume. Waste is a separate allowance you choose for spillage, uneven subgrade, and form movement — MudHub never builds one in without showing you.

Theoretical volume before any waste allowance:

For a small pad, a post footing, or a repair, bagged concrete can be simpler than ordering a truck. The concrete bag calculator converts volume into approximate counts of 40, 60, and 80 lb bags so you can compare.

As a rough guide, one cubic yard is about 45 bags at 80 lb. Once a pour reaches that range, mixing time, labor, and consistency usually make ready-mix worth pricing out. Treat it as a planning comparison — minimum loads and short-load fees vary by supplier.

For contractors, the number is only the start. In MudHub you calculate the yardage, save it to the project, use it in your quote, send a ready-mix order request with the same number, and keep all of it in the concrete Project File.

Two field tools go beyond volume. Both are free, both print for the crew, and both save to a project so you have a record of the conditions on the day of the pour.

How do I calculate how many yards of concrete I need?

Multiply length × width × thickness, all in feet, to get cubic feet, then divide by 27. Thickness is usually measured in inches, so divide inches by 12 first — 4 inches is 0.333 ft. MudHub's concrete volume calculator handles the conversion for you.

How many cubic feet are in a yard of concrete?

One cubic yard is 27 cubic feet (3 ft × 3 ft × 3 ft).

How many bags of concrete equal one cubic yard?

Using the typical yields in MudHub's bag calculator — about 0.30 cu ft per 40 lb bag, 0.45 cu ft per 60 lb bag, and 0.60 cu ft per 80 lb bag — one cubic yard takes about 90 bags at 40 lb, 60 bags at 60 lb, or 45 bags at 80 lb. Check the yield printed on the bag you buy.

How much extra concrete should I calculate for waste?

Waste is a planning allowance you choose. Many contractors add around 5 to 10 percent for spillage, uneven subgrade, and form movement. MudHub lets you set the percentage instead of assuming one.

How thick should I enter a concrete slab?

Enter the actual thickness shown on your plans or specifications. The calculator does not recommend a thickness — that depends on the use, loads, subgrade, and the project specifications.

Do I need an account to use the MudHub calculators?

No. Every MudHub calculator is free to use without an account. A free account lets you save calculations.

Can I save a calculation to a project?

Yes. With an account you can save a calculation to a project, so the yardage sits in the Project File and can be pulled into a quote or a ready-mix order request.