NOVORY

Gravel Calculator

Calculate how much gravel you need for a driveway, pathway, garden bed, or other rectangular project.

Quick answer

Order about 2.7 cubic yards (≈3.8 tons) — most people round to 3 yards.

Calculator

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How it works

Length × Width × Depth = Volume

For imperial inputs, length and width are in feet and depth is in inches. The calculator converts inches to feet automatically, then multiplies the three dimensions to get cubic feet.

Cubic feet ÷ 27 = Cubic yards

Since one cubic yard equals 27 cubic feet (3 ft × 3 ft × 3 ft), dividing by 27 converts the volume to cubic yards — the standard unit for ordering bulk gravel.

The recommended order amount includes your selected waste factor so you have a buffer for compaction and uneven surfaces.

Worked example

A 20 ft × 10 ft driveway at 2 inches deep:

20 × 10 × (2/12) = 33.33 ft³

33.33 ÷ 27 = 1.23 yd³

1.23 × 1.10 = 1.36 yd³ (with 10% waste)

Order approximately 1.36 cubic yards of gravel.

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Gravel is one of the few materials where the ground steals from you twice: the subgrade swallows the first inch, and compaction squeezes another 10–15% out of what you spread. Estimating the geometric volume and ordering exactly that is how driveways end up thin in the middle.

This calculator gives you cubic yards first — the unit quarries think in — then applies a waste factor for compaction and uneven ground. The 10% default covers a prepared subgrade; raw, rutted ground deserves 15%.

How to measure for gravel

  1. Measure the finished area's length and width in feet — where the gravel will actually sit, not the grass around it.
  2. Choose depth by job: 2 inches for garden paths, 3–4 inches for patios and shed bases, 4–6 inches for driveways that carry cars.
  3. Enter depth in inches; the calculator converts to feet and then to cubic yards (÷ 27) automatically.
  4. Confirm tons with the quarry using ~1.4 tons per cubic yard for crushed stone — most bulk yards sell by weight, and the scale doesn't negotiate.

Yards and tons by project size (4 in deep, ≈1.4 tons/yd³)

AreaCubic yardsTons
10 × 10 ft1.231.7
10 × 20 ft2.473.5
12 × 12 ft1.782.5
20 × 20 ft4.946.9

Weight varies with stone type and moisture. Confirm your quarry's own tons-per-yard figure before paying by weight.

Worked example: gravel for a 10×20 driveway

A 10 ft × 20 ft driveway, 4 inches of crushed stone:

  1. Convert depth: 4 ÷ 12 = 0.333 ft.
  2. Volume: 10 × 20 × 0.333 = 66.67 ft³.
  3. To cubic yards: 66.67 ÷ 27 = 2.47 yd³.
  4. To tons: 2.47 × 1.4 = 3.46 tons.
  5. With 10% for compaction: 2.47 × 1.10 = 2.72 yd³.

Order about 2.7 cubic yards (≈3.8 tons) — most people round to 3 yards.

Pro tips for ordering gravel

  • Compact in lifts: spread no more than 3–4 inches at a time and compact each lift. One thick layer never compacts evenly.
  • Crushed angular stone locks together; round pea gravel migrates. For driveways and paths that stay put, crushed is the answer.
  • Slope for drainage: ¼ inch per foot away from structures. Flat gravel holds puddles; puddles become potholes.
  • Order the full depth in one delivery. A second small load often costs more in delivery fees than the extra stone would have.

How to use the gravel calculator

1. Choose your unit system — Imperial (feet and inches) or Metric (meters and centimeters).

2. Enter the length and width of your project area.

3. Enter the depth of gravel you need.

4. Select a waste factor — 10% is recommended for most projects to account for compaction.

5. Click Calculate to see your results in cubic yards, cubic feet, and cubic meters.

How gravel volume is calculated

Gravel volume is calculated by multiplying the three dimensions of your project: length, width, and depth. This gives you the total volume of space the gravel will fill.

In the imperial system, the result is in cubic feet. Since bulk gravel is often sold by the cubic yard, the calculator divides by 27 to convert. In the metric system, the result is directly in cubic meters.

The waste factor is applied as a percentage increase to the base volume, giving you a recommended order amount that accounts for compaction, spillage, and uneven surfaces.

How much gravel do I need?

The amount of gravel you need depends on the size and depth of your project. A small pathway might need less than 1 cubic yard, while a long driveway could require several cubic yards.

Always measure carefully and add a waste factor. Gravel compacts after installation, so ordering slightly more than the calculated volume ensures you have enough to achieve the desired finished depth.

Why add a waste factor?

A waste factor accounts for gravel that is lost to compaction, spillage, over-excavation, or uneven ground. Without a buffer, you risk running short and needing a second delivery.

The standard recommendation is 10%. For deeper installations or projects on soft ground, 15% is safer. For simple, well-prepared areas with precise measurements, 5% may be enough.

Gravel calculator example

Let's say you're covering a driveway that is 20 feet long, 10 feet wide, and 2 inches deep.

First, convert the depth to feet: 2 inches ÷ 12 = 0.167 feet.

Then calculate the volume: 20 × 10 × 0.167 = 33.33 cubic feet.

Convert to cubic yards: 33.33 ÷ 27 = 1.23 cubic yards.

With a 10% waste factor: 1.23 × 1.10 = 1.36 cubic yards.

You should order approximately 1.36 cubic yards of gravel for this project.

Frequently Asked Questions

How do I calculate how much gravel I need?+
Multiply the length by the width by the depth of your project area. Make sure the dimensions use compatible units. In imperial units, this produces cubic feet, which can be divided by 27 to convert to cubic yards. In metric units, the result is cubic meters. Add a waste factor to allow for compaction, spillage, and minor measurement differences.
How many cubic yards of gravel do I need?+
Calculate the volume in cubic feet by multiplying length × width × depth, with all dimensions converted to feet. Then divide the result by 27. For example, a 20 ft × 10 ft area at 2 inches deep has a base volume of approximately 1.23 cubic yards before waste.
How deep should gravel be?+
For driveways and pathways, a compacted depth of 2–4 inches is common. For decorative landscaping, 2–3 inches is typical. For drainage projects, depth depends on the specific application. Always account for compaction — gravel settles and compacts over time, so ordering slightly more than the calculated volume is recommended.
What is the difference between cubic feet and cubic yards?+
A cubic yard is equal to 27 cubic feet. One cubic yard measures 3 feet × 3 feet × 3 feet. Bulk gravel is commonly ordered by the cubic yard, while bagged gravel is often sold by the cubic foot.
Should I account for compaction when ordering gravel?+
Yes. Gravel compacts after installation, meaning the installed volume will be less than the loose volume you order. A waste factor of 10% is commonly recommended to account for compaction, spillage, and uneven surfaces. For deeper installations or projects on soft ground, 15% may be more appropriate.

Related Guides

How to Calculate Gravel for a DrivewayHow Much Gravel Do I Need for a 10x20 Driveway?How Much Gravel Do I Need for a 12x12 Shed Base?

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