Why use a calculator before you buy?
Ordering too little material means a second trip to the store, a mismatched batch, or a concrete pour that runs short halfway through. Ordering too much wastes money on bags and yards you cannot return. A few seconds with the right formula avoids both.
Every calculator on this site shows the formula it uses, so you can check the math yourself, and each one lets you add a waste allowance and a price so you can budget the whole project before you start.
How to measure accurately
- Use a tape measure, not a guess. Measure each side twice and round up to the nearest inch.
- Split odd shapes into simple ones. An L-shaped room is two rectangles. A curved bed is close to a circle or half circle.
- Write the units down. Mixing inches and feet is the most common reason estimates come out wrong.
- Add a waste allowance. 5% to 10% covers cuts, spills, uneven ground and breakage on most jobs.
Which calculator do I need?
| Project | Calculator |
|---|---|
| Flooring, carpet, sod, home size | Square footage |
| Floor, wall and backsplash tile | Tile |
| Patio, driveway, footing, post holes | Concrete |
| New roof, shingles, underlayment | Roofing and roof pitch |
| Wood privacy or picket fence | Fence |
| Hanging and finishing walls | Drywall |
| Walls, ceilings, whole rooms | Paint |
| Driveway base, paths, drainage | Gravel |
| Garden beds, around trees, playgrounds | Mulch |
| New lawns, raised beds, leveling | Topsoil |