Answer first
What this calculator tells you
Calculate the cubic yards and tons of gravel needed to cover a path, a driveway or a bed. Order stone by the ton for a surface of a given area and depth. Formula: Cubic yards = area × depth (in) ÷ 12 ÷ 27; tons = cubic yards × weight per cubic yard. At the worked-example inputs, the gravel needed (cubic yards) is 5.6. Holding every other input steady, moving area to cover (sq ft) from 480 to 720 moves the result from 4.4 to 6.7.
Transparent method
The formula
Order stone by the ton for a surface of a given area and depth.
Worked example
Example inputs
How to interpret the result
A gravel surface is a layer, so the volume is area times depth. A 600 square foot area at 3 inches deep is 150 cubic feet, or 5.6 cubic yards. Stone is often sold by the ton, and at about 1.4 tons per cubic yard that is nearly 7.8 tons.
At the worked-example inputs the gravel needed (cubic yards) is 5.6. It rises with area to cover (sq ft) and gravel depth (in); weight per cubic yard (tons) does not move it.
These are quantity estimates from the area and depth you enter. Real yards have slopes, curves and settling, and bulk materials vary in weight with moisture, so order a little extra and confirm coverage, bag sizes and rates with the product label or your supplier. Fertilizer and seed rates depend on your grass, soil and region, so follow the label and your local extension office.
Before you rely on it
What to check
Match the depth to the use. A path holds up with 2 inches, but a driveway wants 4 to 6 inches over a compacted base, so the same area can need twice the stone.
The common error
Where people go wrong with gravel calculator
Forgetting compaction. Crushed stone packs down by about 10 to 15 percent under traffic, so a driveway ordered to the exact volume ends up thin.
Sensitivity evidence
How area to cover (sq ft) changes the gravel needed (cubic yards)
Holding every other input at the worked-example value, moving area to cover (sq ft) from 480 to 720 moves the gravel needed (cubic yards) from 4.4 to 6.7: a spread of 2.2, or 40% of the worked-example result.
| Area to cover (sq ft) | Gravel needed (cubic yards) | Weight (tons) |
|---|---|---|
| 480 | 4.4 | 6.2 |
| 540 | 5 | 7 |
| 600worked example | 5.6 | 7.8 |
| 660 | 6.1 | 8.6 |
| 720 | 6.7 | 9.3 |
Every input, tested
Which input moves the gravel needed (cubic yards) most
Of the 3 inputs, area to cover (sq ft) moves the gravel needed (cubic yards) most (1.1 across the range tested) and gravel depth (in) moves it least (1.1). Weight per cubic yard (tons) does not change it at all.
| Input | Tested from | To | Gravel needed (cubic yards) at each end | Swing |
|---|---|---|---|---|
| Area to cover (sq ft) | 540 | 660 | 5 to 6.1 | 1.1 (20%) |
| Gravel depth (in) | 2.7 | 3.3 | 5 to 6.1 | 1.1 (20%) |
| Weight per cubic yard (tons) | 1.3 | 1.5 | 5.6 to 5.6 | none |
Two variables at once
Gravel needed (cubic yards) by area to cover (sq ft) and gravel depth (in)
Across the grid the gravel needed (cubic yards) runs from 3.6 to 8. Moving area to cover (sq ft) from 480 to 720 shifts it by 2.2 at the middle column, and moving gravel depth (in) from 2.4 to 3.6 shifts it by 2.2 at the middle row, so neither is the bigger lever here.
| Area to cover (sq ft) \ Gravel depth (in) | 2.4 | 3 | 3.6 |
|---|---|---|---|
| 480 | 3.6 | 4.4 | 5.3 |
| 540 | 4 | 5 | 6 |
| 600 | 4.4 | 5.6 | 6.7 |
| 660 | 4.9 | 6.1 | 7.3 |
| 720 | 5.3 | 6.7 | 8 |
The highlighted cell is the worked example: 5.6.
Step by step
The worked example, input by input
| Input | Value used | What it means |
|---|---|---|
| Area to cover (sq ft) | 600 | Enter the area to cover (sq ft) used in this calculation. |
| Gravel depth (in) | 3 | 2 to 4 inches is common for a path or driveway top layer. |
| Weight per cubic yard (tons) | 1.4 | Crushed stone and gravel run about 1.3 to 1.6 tons per cubic yard, depending on the stone and its moisture. |
| Gravel needed (cubic yards) | 5.6 | |
| Weight (tons) | 7.8 | |
Inputs, definitions and assumptions
Area to cover (sq ft)
Enter the area to cover (sq ft) used in this calculation. The prefilled worked-example value is 600.
Gravel depth (in)
2 to 4 inches is common for a path or driveway top layer. The prefilled worked-example value is 3.
Weight per cubic yard (tons)
Crushed stone and gravel run about 1.3 to 1.6 tons per cubic yard, depending on the stone and its moisture. The prefilled worked-example value is 1.4.
How to use this calculator
- 1Verify the inputs. Gather area to cover (sq ft), gravel depth (in) and weight per cubic yard (tons) from your own documents; the prefilled values are examples.
- 2Save a baseline. The worked example puts the gravel needed (cubic yards) at 5.6. Store your own version of it as Scenario A.
- 3Test one change. Start with area to cover (sq ft), the input with the biggest effect here: moving area to cover (sq ft) from 540 to 660 takes the gravel needed (cubic yards) from 5 to 6.1, a swing of 20% of the worked-example figure.
- 4Check the extremes. At half the example area to cover (sq ft) (300) the gravel needed (cubic yards) is 2.8; at double (1,200) it is 11.1.
People also ask
Frequently asked questions
How do you calculate gravel?
Cubic yards = area × depth (in) ÷ 12 ÷ 27; tons = cubic yards × weight per cubic yard. At the worked-example inputs the gravel needed (cubic yards) is 5.6.
What does the gravel result mean?
Order stone by the ton for a surface of a given area and depth. At the worked-example inputs the gravel needed (cubic yards) is 5.6. It rises with area to cover (sq ft) and gravel depth (in); weight per cubic yard (tons) does not move it.
How much does area to cover (sq ft) change the gravel needed (cubic yards)?
Holding every other input at the worked-example value, moving area to cover (sq ft) from 480 to 720 moves the gravel needed (cubic yards) from 4.4 to 6.7, a spread of 2.2.
What are the limits of this gravel calculator?
These are quantity estimates from the area and depth you enter. Real yards have slopes, curves and settling, and bulk materials vary in weight with moisture, so order a little extra and confirm coverage, bag sizes and rates with the product label or your supplier. Fertilizer and seed rates depend on your grass, soil and region, so follow the label and your local extension office. The tables on this page test area to cover (sq ft) only from 480 to 720; a value outside that range is not tabulated here.
Which input moves the gravel needed (cubic yards) most in the gravel calculator?
Ranked by how far each moves the gravel needed (cubic yards) across the range tested: area to cover (sq ft) (1.1, 20%) and gravel depth (in) (1.1, 20%). Weight per cubic yard (tons) does not change it.
If I double area to cover (sq ft) in the gravel calculator, does the gravel needed (cubic yards) double?
Doubling it from 600 to 1,200 takes the gravel needed (cubic yards) from 5.6 to 11.1, which is 2.00 times the worked-example figure. So the result scales almost exactly in proportion. Halving it to 300 gives 2.8.
How much does gravel depth (in) matter in the gravel calculator?
The worked example uses 3. With the other inputs left at the worked example, moving gravel depth (in) from 2.7 to 3.3 takes the gravel needed (cubic yards) from 5 to 6.1, a swing of 20% of the worked-example figure.
How much does weight per cubic yard (tons) matter in the gravel calculator?
The worked example uses 1.4. The gravel needed (cubic yards) does not depend on weight per cubic yard (tons); it moves the weight (tons) from 7 to 8.6 instead when weight per cubic yard (tons) goes from 1.3 to 1.5.
Which inputs change the weight (tons) in the gravel calculator?
At the worked-example inputs it is 7.8. Area to cover (sq ft) takes it from 7 to 8.6, gravel depth (in) takes it from 7 to 8.6 and weight per cubic yard (tons) takes it from 7 to 8.6.
How do I read the numbers on a fertilizer bag?
They are the percent nitrogen, phosphorus and potassium by weight. A 20-5-10 bag is 20 percent nitrogen, so 15 pounds of it holds 3 pounds of nitrogen.
When is the best time to seed a lawn?
Early fall for cool-season grasses, when soil is warm and air is cool, and late spring for warm-season grasses. Both need about 2 to 3 weeks of even moisture to sprout.
Do these calculators handle sloped or curved beds?
They use a flat area you enter. For a curve, split the bed into rectangles and circles, add their areas, and add 5 to 10 percent for the awkward edges.
Sources and evidence
Free Calculators Online is independent and is not affiliated with or endorsed by the source organizations. Educational estimates only.