Measure right. Buy the right amount.

Free calculators for paint, mulch, concrete, and the rest of your project list. Each one shows its formula, names the manufacturer spec behind every number, and rounds the answer up to whole gallons and bags.

Painting & Finishing

Landscaping

Concrete & Masonry

Interior

Where the numbers come from

Every calculator on this site prints its formula on the page, so you can check the math yourself.

Coverage and yield numbers come from manufacturer specs, with the source named and the date it was checked. When two good sources disagree, we say so and explain which one the calculator uses.

Results round up to what a store actually sells: whole gallons, whole bags, whole rolls. The raw math sits right next to the rounded number.