Know exactly how much material to order.
DirtMath turns a bed size and a depth into cubic yards, tons, bag counts and a delivered-cost estimate — for twelve of the materials landscapers buy most. No sign-up, no guessing, no ordering two yards too many.
All calculators
- Mulch CalculatorA cubic yard of mulch covers about 108 square feet at 3 inches deep, so most beds need roughly 1 cubic yard (13.5 two-cubic-foot bags) per 100 square feet.
- Topsoil CalculatorOne cubic yard of screened topsoil covers about 108 square feet at 3 inches deep and weighs roughly 1.1 tons.
- Gravel CalculatorOne cubic yard of gravel weighs about 1.4 tons and covers roughly 81 square feet at 4 inches deep — the standard depth for a driveway layer.
- Sand CalculatorOne cubic yard of sand weighs about 1.35 tons and covers roughly 324 square feet at a 1-inch paver bedding depth.
- River Rock CalculatorOne ton of river rock covers about 70 to 80 square feet at 3 inches deep, depending on stone size.
- Sod CalculatorA standard pallet of sod covers about 450 square feet, and a single roll covers about 10 square feet.
- Grass Seed CalculatorA new lawn needs about 1 pound of grass seed per 250 square feet; overseeding an existing lawn takes about half that.
- Compost CalculatorOne cubic yard of compost topdresses about 650 square feet of lawn at a quarter inch, or fills 108 square feet of bed at 3 inches deep.
- Paver CalculatorA 12 × 12 inch paver covers exactly 1 square foot, so a 200 square foot patio needs 200 pavers plus about 10 percent for cuts.
- Retaining Wall Block CalculatorA 20-foot-long, 2-foot-high wall built from 6 × 16 inch blocks needs about 60 blocks plus 15 caps.
- Rubber Mulch CalculatorA playground needs 6 inches of rubber mulch for a 6-foot fall height, which is about 40 bags (0.8 cu ft each) per 100 square feet.
- Pine Straw CalculatorOne bale of pine straw covers about 50 square feet at a settled depth of 2 to 3 inches.
Measure in zones
Odd-shaped beds are easier as two or three rectangles and a circle. Every calculator lets you add areas and totals them for you.
Depth decides everything
One cubic yard covers 162 sq ft at 2 inches but only 81 sq ft at 4. Pick the depth before you price anything.
Bulk beats bags fast
Past about six bags, loose delivery is almost always cheaper per cubic foot — the calculators show both so you can compare.