Gravel Calculator

How to Calculate Gravel Volume and Weight

Gravel is ordered by volume (cubic yards) but often priced and delivered by weight (tons), so this calculator does both conversions. Start with area times depth to get cubic feet, convert to cubic yards by dividing by 27, then multiply by the material's density to get weight in pounds, and divide by 2,000 to get tons.

$$\text{Weight (tons)} = \frac{A \times (D \div 12)}{27} \times \frac{\rho}{2000}$$

Worked Example

A 300 sqft driveway area at a 4-inch depth: volume = 300 × (4 ÷ 12) = 100 cubic feet, or 100 ÷ 27 ≈ 3.7 cubic yards. At crushed stone's density of 2,700 pounds per cubic yard, that's 3.7 × 2,700 ≈ 10,000 pounds, or about 5 tons. At 40 dollars a ton, that's roughly 200 dollars in material before delivery.

Metric Version of the Formula

Outside the US, the same calculation works in square meters, centimeters, and metric tonnes instead — switch the US/Metric dropdown above to convert your currently entered area and depth automatically. Weight converts cleanly too, since a US short ton (907.18 kg) and a metric tonne (1,000 kg) are both real, exactly-defined units — unlike a bagged product size, there's no fabricated metric equivalent involved.

$$\text{Weight (tonnes)} = A \times (D \div 100) \times \rho_{kg/m^3} \div 1000$$

A 30 m² driveway area at a 10 cm depth: volume = 30 × (10 ÷ 100) = 3 cubic meters. At crushed stone's density (converted to about 1,600 kg/m³), that's roughly 4.8 tonnes.

Why Material Density Matters

Different materials pack to different densities depending on particle size, shape, and moisture content — this is why the same volume of two different materials can weigh noticeably different amounts, and why gravel suppliers quote by weight even though you're really buying a volume to fill a space. Crushed stone and pea gravel land close to each other around 2,700-2,800 pounds per cubic yard; topsoil is notably lighter, around 2,000 pounds per cubic yard, since it's a looser mix with more organic material and air pockets.

Common Gravel Calculation Mistakes

Forgetting to convert depth from inches to feet before multiplying is the most common error, same as with any volume calculation involving a thin layer over a wide area. Assuming all gravel materials weigh the same per cubic yard is the second — using crushed stone's density to price topsoil overstates the weight (and likely the cost) by roughly 25-30%. Not accounting for compaction is the third: loose material settles once compacted or driven over, so a thin layer can end up thinner than intended if depth wasn't measured generously to begin with.

Gravel Terms You Should Know

Crushed Stone — angular, mechanically crushed rock; interlocks well and compacts firmly, a common driveway base material.

Pea Gravel — small, rounded stones, popular for walkways and drainage since it doesn't compact as firmly as angular crushed stone.

Subgrade — the native soil beneath a gravel layer; an uneven or soft subgrade can require extra material to level and stabilize.

Density (Bulk Density) — a material's weight per unit volume, typically given in pounds per cubic yard for landscaping and construction aggregates.