How to use it
Pick the material, then type the length and width of the area and how deep you want it. The answer is in cubic yards, which is how bulk material is usually sold, with cubic feet and the same amount with 10% extra. For gravel, sand and topsoil you also get an approximate weight in tons. Mulch is given in 2 cubic foot bags.
Worked examples
- Gravel. A pad 20' × 10' and 4" deep is 66.67 cu ft, which is 2.47 cu yd, or 2.72 cu yd with 10% extra. At 1.4 tons per cubic yard that is about 3.46 tons.
- Mulch. A bed 12' × 4' and 3" deep is 12 cu ft, which is 0.44 cu yd, or 6 bags of the 2 cubic foot size.
Weights used
Tons are worked out from a typical weight for each material. Real loads vary a good deal with moisture and the size and mix of the stone, so treat the tons as a guide and ask your supplier what their material weighs.
| Material | Per cubic yard | In pounds |
|---|---|---|
| Gravel | 1.4 tons | 2,800 lb |
| Sand | 1.35 tons | 2,700 lb |
| Topsoil | 1.1 tons | 2,200 lb |
The math
- Volume = length × width × depth, all in feet, which gives cubic feet. Divide by 27 for cubic yards.
- Tons = cubic yards × the weight per cubic yard.
- The depth is the finished depth. Gravel and soil settle when compacted, which is one reason to order extra.
Typing measurements
Every box takes feet, inches and fractions the way you would write them: 9' 1 1/8", 7 1/2", 2.5' or 300mm. Put a space between whole inches and a fraction. A box also takes a whole calculation, so 14' 6" / 2 works anywhere.
Questions
How much gravel do I need?
Multiply the length by the width by the depth in feet and divide by 27 for cubic yards. A 20' × 10' area 4 inches deep takes 2.47 cubic yards, about 3.46 tons.
How many tons are in a cubic yard of gravel?
About 1.4 tons, or 2,800 pounds, for typical gravel. It varies with the stone and how wet it is, so check with your supplier.
How much area does a cubic yard cover?
A cubic yard is 27 cubic feet. Spread 3 inches deep it covers 108 square feet, and 4 inches deep it covers 81 square feet.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it takes 14 bags of the 2 cubic foot size.
Should I order extra?
Usually. The ground is uneven, material settles when it is compacted, and a second small delivery costs more than a little left over. The calculator shows every amount with 10% added.
More calculators
- Feet & inches calculatorAdd, subtract, multiply and divide feet, inches and fractions. Free, nothing to install.
- Decimal feet to feet & inches converterType a length in any one box: decimal feet, feet and inches, inches or millimeters. The other three fill in.
- Roof pitch & rafter length calculatorEnter any two of pitch, rise, run and diagonal. The other two fill in.
- Stair calculatorEnter the floor-to-floor rise to get risers, treads, total run and stringer length.
- Circle & arc calculatorEnter a diameter for circumference and area. Add an angle for arc length and chord.
- Square footage & volume calculatorEnter length and width for area. Add a height for volume, cubic yards and wall area.
- Stud & on-center spacing calculatorEnter a length and a spacing to get the member count, the last bay and the equal spacing.
- Concrete calculatorPick slab, footing, wall or round column, type the size in feet and inches, and get cubic yards and bags.
- Slope converterType a slope as inches per foot, percent, degrees or a ratio. The other three fill in.
- Drawing scale calculatorEnter a scale and a length to convert it, or a drawn length and its real size to find the scale.
Reference finders
- DSA forms & publications finderType a topic or a number, or paste a plan check comment, and see which DSA documents to open.
- OSHPD / HCAI CAN, PIN & forms finderType a topic or a number, or paste a plan review comment, and see which HCAI documents to open.