How much material do you need to buy?
Measure your area and depth. Get the cubic yards, tons and bags to order, with the formula shown.
- GravelCubic yards, tons and bags for driveways, paths and patio bases
- TopsoilCubic yards, tons and bags for lawns, garden beds and raised beds
- MulchBags or cubic yards of mulch for beds and borders
- ConcreteCubic yards and 80, 60 or 40 lb bags for slabs, footings and post holes
- Square footageSquare feet, square yards, square meters and acres for rooms, floors and lots
Every calculator does the same sum
One engine, tested against hand-worked examples. Each tool shows you the numbers it used.
- L × WAreaor πr² for circles, ½ × base × height for triangles
- × DCubic feetarea times depth, in feet
- ÷ 27Cubic yards27 cu ft in a cubic yard
- + %Allowancefor waste, settling or compaction
- × tTonscubic yards times material density
- ÷ bagBagsvolume over bag size, rounded up
Can you trust the numbers?
The arithmetic is exact and checked by automated tests. The bit that varies is the material itself: a yard of wet gravel weighs more than a dry one, and bag yields differ by brand.
So treat every result as a planning estimate, add the allowance, and confirm the figure with your supplier before you order. Every tool lists the densities and bag sizes it uses.
Guides
- Bags vs bulk: when a truckload is cheaper
How to tell whether bagged or bulk gravel, soil and mulch costs less for your project, with a break-even formula and a worked example.
- How deep should gravel be for a driveway, patio or path?
Recommended gravel depths for driveways, patio bases, paths and decorative beds, plus the tonnage each depth needs per 100 square feet.
- How to measure an irregular area for landscaping materials
Split curved or L-shaped beds into rectangles, triangles and circles, or use a grid, to get an accurate area for mulch, soil, gravel or concrete.