About BuildCalc

A small set of calculators for people who buy materials by the yard, the ton and the gallon.

Why this exists

The numbers on a bag of concrete or a can of paint are printed for a reason, but most online calculators hide the math behind a form. If the result looks wrong, you have no way to tell whether the tool is wrong or your input was. Every calculator here shows the formula, the yield it assumes, and a worked example you can reproduce with a pencil.

How the numbers are validated

Each tool is checked against the manufacturer-published yield for the product category and against a hand calculation of at least two real jobsite examples. Where sources disagree — gravel density is the usual offender — the range is stated and the input is adjustable instead of hidden.

What this is not

Not engineering. Not a substitute for a licensed contractor, a structural calculation, or your local building department. Estimates are for planning and purchasing; the supplier's ticket is the final word.

Corrections

Found a wrong number? Send the calculator, the inputs and the result you expected to buildcalc.contact@proton.me.