Gravel & Mulch Calculator

How to use this calculator

Choose the material first; its typical bulk density is used to turn volume into weight. Then enter the length and width of the area (or the area directly if the shape is irregular) and the depth you want. The volume is shown in cubic yards, the unit most US landscape suppliers sell by, and the weight in US tons, which is how quarries price stone.

Typical depths: 2–3 in for decorative gravel and mulch beds, 4 in for walkways, 4–6 in of compacted base for patios, and 6–8 in for driveways. You can also work backwards — enter the cubic yards in a delivery to see how large an area it will cover at a given depth.

The formula

A = l × w

V = A × d

m = V × ρ_material

l: length
w: width
A: area
d: depth
V: volume
m: weight

Worked example

A 10 × 10 ft patio base needs 3 inches of crushed gravel.

Area = 10 × 10 = 100 ft².
Volume = 100 ft² × 0.25 ft = 25 ft³ = 0.93 yd³.
Weight = 0.708 m³ × 1,680 kg/m³ = 1,189 kg ≈ 1.31 US tons.

Order one cubic yard, which most yards sell as roughly 1.3–1.4 tons of crushed stone.

Assumptions and limits

Bulk densities are typical loose values; moisture and particle size change them by ±15%. Wet sand can be 20% heavier than dry.
Compaction reduces volume: for a compacted base add about 10–15% to the ordered amount.

Frequently asked questions

How many square feet does a cubic yard cover?

At 3 inches deep, one cubic yard covers 108 ft²; at 2 inches, 162 ft²; at 4 inches, 81 ft².

How much does a cubic yard of gravel weigh?

Roughly 1.3–1.5 US tons (2,600–3,000 lb) depending on stone and moisture. Mulch weighs only 400–800 lb per cubic yard.

How many bags of mulch equal a yard?

One cubic yard is 27 ft³, so it takes 13.5 bags of 2 ft³ or 9 bags of 3 ft³.