About Yard & Gallon
Calculators that show their work
Yard & Gallon is a free set of calculators for US home projects: how many bags of concrete for a slab, how much mulch for a bed, how many gallons of paint for a room, how many risers a staircase needs. Each calculator shows the formula it uses and cites the source behind every default number, so you can check it before you spend money.
Owner and editor
Erdi Doğan
Erdi Doğan owns and edits Yard & Gallon and is responsible for everything published on it. Calculators and guides are drafted with AI assistance; every number is checked against the cited source before it goes live.
Where the numbers come from
- Manufacturer data sheets for anything printed on a product: concrete bag yields (QUIKRETE, Sakrete), paint coverage per gallon (Sherwin-Williams, Benjamin Moore, BEHR, Valspar), shingle bundles per square and ridge cap coverage (GAF, Owens Corning).
- Building codes for limits: stair risers, treads, headroom and width from the International Residential Code (R311.7), and the minimum slope for asphalt shingles (R905.2), as reprinted by city and county building departments.
- Extension services and public agencies for landscaping depths and material weights.
- Plain arithmetic for unit conversions (27 cubic feet in a cubic yard, 100 square feet in a roofing square), which needs no source.
How a calculator is made
- We collect the source pages first and copy each number with its exact wording and link.
- The page and calculator are drafted with AI assistance from those sources.
- Every number on the page is checked against the cited source. If a number cannot be traced, it is cut, or the calculator asks you to type the value from your own product's label.
- We test each calculator against hand math before it goes live.
What we do not do
- We do not invent product numbers, personal stories or expert personas.
- We do not accept payment from manufacturers. Brand names appear only because their data sheets are the source.
- We are not your building inspector. Local codes, permits and engineered plans take priority over anything here.
Estimates only
Results are estimates for planning and shopping. Check local codes and your product's label, and use the waste allowance each calculator explains.
Corrections
Found a number that does not match its source, or a better source? Please tell us. We fix errors and update the date on the page when we do.