How to use the asphalt thickness calculator calculator
- 1
Choose a mode
Pick Known cubic yards, Known tons and density, or Known thickness depending on what you have.
- 2
Enter the area
Enter the project area in square feet in every mode.
- 3
Enter the other value
Add the cubic yards, or the tons with a density, or the thickness with an optional density.
- 4
Review the result
Read the thickness in several units, or the volume and tons, depending on the mode.
Formula
Thickness (in) = cubic yards x 324 / area in square feet
Spreading a volume over an area gives a depth: cubic yards times 324 divided by the area in square feet is the thickness in inches. To start from tons, convert tons to cubic yards with a density first.
Worked example
You have 5 cubic yards of asphalt to spread over a 600 square foot area.
- 1Apply the formula: 5 x 324 / 600 = 2.7 inches.
- 2In feet that is 2.7 / 12 = 0.225 feet.
- 3In millimeters that is 2.7 x 25.4 = 68.58 millimeters.
Spread evenly, 5 cubic yards over 600 square feet is about 2.7 inches thick.
Worked examples
Tons to thickness
10 tons over 800 square feet, with a density of 145 pounds per cubic foot entered by the user.
- 1Cubic yards: 10 x 2,000 / (27 x 145) = 5.11 cubic yards.
- 2Thickness: 5.11 x 324 / 800 = 2.07 inches.
- 3The density is needed to turn tons into a volume first.
At the entered density, 10 tons over 800 square feet is about 2.07 inches.
Thickness to volume
A 600 square foot area at a 3 inch thickness.
- 1Cubic yards: 600 x 3 / 324 = 5.56 cubic yards.
- 2Cubic feet: 5.56 x 27 = 150 cubic feet.
- 3Add a density to also estimate tons.
A 600 square foot area at 3 inches is about 5.56 cubic yards.
Area, volume, and thickness relationship
Volume, area, and thickness are three sides of one relationship: volume equals area times thickness. Know any two and you can solve for the third. Spreading a fixed volume over a larger area makes a thinner layer, and over a smaller area a thicker one.
This calculator rearranges that relationship for each mode. Given a volume and an area it returns the thickness, and given an area and a thickness it returns the volume. The math is the same as the coverage relationship in cubic yards to square feet.
Tons to thickness, and why density is needed
If you start from a tonnage, the calculator first converts it to a volume, because thickness comes from volume and area, not weight. That conversion needs the density of your mix: cubic yards equal tons times 2,000 divided by 27 times the density.
Once the tons become a volume, the thickness follows from the same area formula. Because the density drives the volume, the thickness estimate is only as specific as the density you enter, which should come from your mix or supplier.
Using thickness to check a delivery
Thickness math is a quick way to sanity check an order. If you know the area you are paving and the volume or tonnage on order, the calculator shows the average thickness that amount would spread to. Comparing that against the thickness your plan calls for tells you whether the order is roughly right.
For example, a delivery that spreads to well under your planned thickness suggests the order is short for the area, while a much greater thickness suggests too much for that footprint. Treat it as a rough check, since real spread is never perfectly even.
Planning and specification note
Use this tool to check how a known amount of asphalt spreads, to compare volume and tonnage figures, or to convert a thickness into a quantity. It answers the arithmetic question of how thick a layer would be, not the engineering question of how thick it should be.
For the quantity side of a project, the asphalt calculator sizes volume and tons from dimensions, and how to calculate cubic yards covers the underlying method.
Common mistakes
Watch for these when working with thickness:
- Treating a geometric thickness as a recommended or code thickness
- Starting from tons without entering a density
- Mixing units, such as an area in square yards with a thickness in inches
- Using the outside footprint instead of the paved area
- Assuming an even spread when real ground varies
Cubic Yards Required by Area and Thickness
Cubic yards for each area and thickness. Read your area on the left and the thickness across the top.
| Area | 1 in | 2 in | 3 in | 4 in | 6 in |
|---|---|---|---|---|---|
| 200 sq ft | 0.617 | 1.23 | 1.85 | 2.47 | 3.7 |
| 400 sq ft | 1.23 | 2.47 | 3.7 | 4.94 | 7.41 |
| 600 sq ft | 1.85 | 3.7 | 5.56 | 7.41 | 11.11 |
| 800 sq ft | 2.47 | 4.94 | 7.41 | 9.88 | 14.81 |
| 1,000 sq ft | 3.09 | 6.17 | 9.26 | 12.35 | 18.52 |
| 1,500 sq ft | 4.63 | 9.26 | 13.89 | 18.52 | 27.78 |
| 2,000 sq ft | 6.17 | 12.35 | 18.52 | 24.69 | 37.04 |
Coverage From One Cubic Yard at Different Thicknesses
Square feet that one cubic yard covers at each thickness, from 324 divided by the thickness in inches.
| Cubic yards | 1 in | 2 in | 3 in | 4 in | 6 in | 8 in |
|---|---|---|---|---|---|---|
| 1 | 324 sq ft | 162 sq ft | 108 sq ft | 81 sq ft | 54 sq ft | 40.5 sq ft |
Tons-to-Thickness Density Mathematics
Mathematical examples by entered density, used when starting from tons. These are not asphalt material specifications. Each row shows what one cubic yard weighs at that density.
| Entered density (lb/ft³) | Pounds per cubic yard | US short tons per cubic yard | Metric tonnes per cubic yard |
|---|---|---|---|
| 50 | 1,350 | 0.675 | 0.612 |
| 75 | 2,025 | 1.01 | 0.919 |
| 100 | 2,700 | 1.35 | 1.22 |
| 125 | 3,375 | 1.69 | 1.53 |
| 150 | 4,050 | 2.03 | 1.84 |
Frequently asked questions
- How do I calculate asphalt thickness?
- Divide the asphalt volume by the area. In inches, thickness equals cubic yards times 324 divided by the area in square feet. For 5 cubic yards over 600 square feet, that is 2.7 inches.
- How do I find thickness from tons?
- Convert tons to a volume with the density of your mix, then divide by the area. The density is required because thickness comes from volume, not weight.
- Does this tool recommend an asphalt thickness?
- No. It calculates the geometric thickness from your numbers. It does not recommend or approve a thickness for any driveway, road, parking lot, structural, or code application.
- How much does one cubic yard of asphalt cover?
- It depends on thickness. One cubic yard covers 324 square feet at 1 inch, 162 square feet at 2 inches, and 108 square feet at 3 inches.
- Can I find the volume from a thickness?
- Yes. Use the Known thickness mode with the area, and the calculator returns the cubic feet and cubic yards, plus tons if you add a density.
- Why do I need the area in every mode?
- Because thickness and volume both relate to the area. The area is the common term that links a volume or tonnage to a layer thickness.
Thickness uses the exact relationship that one cubic yard equals 324 square feet at 1 inch deep. Tonnage steps use a density you enter. Every value is geometric and is not a recommended or approved thickness. See the YardCalc calculation methodology.
Results are planning estimates. Last reviewed 2026-07-07.