Gravel Calculator
Work out how much gravel a driveway, patio, path or bed needs in cubic yards, tons and bags, with an allowance for settling and an optional cost.
Bag size and price (optional)
Fills 200 ft² at 3 in deep, with 10% extra for settling and spreading.
Rectangle 20 × 10 ft, gravel or crushed stone at 2,700 lb per yd³.
Weight to order
At 2,700 lb per yd³ (1.35 tons per yd³). Yards sell gravel by the ton or the cubic yard, so ask which density they use: it changes the weight, not the volume.
Your calculation
The same steps the calculator runs, with your numbers.
- Area: 20 × 10 = 200 ft².
- Depth in ft: 3 ÷ 12 = 0.25 ft. Volume: 200 × 0.25 = 50 ft³, ÷ 27 = 1.852 yd³.
- Add 10%: 1.852 × 1.1 = 2.037 yd³.
- Weight: 2.037 × 2,700 lb = 5,500 lb, ÷ 2,000 = 2.75 tons.
- Bags: 5,500 ÷ 50 = 110 bags.
Same area at other depths
Same area, material and extra allowance, with only the depth changed.
| Depth | Volume (yd³) | Weight (tons) |
|---|---|---|
| 2 in | 1.36 | 1.83 |
| 4 in | 2.72 | 3.67 |
| 6 in | 4.07 | 5.50 |
| 8 in | 5.43 | 7.33 |
| 12 in | 8.15 | 11.00 |
An estimate from the dimensions you enter. Gravel weight varies with stone type, size and moisture, so confirm the density your supplier uses before ordering by the ton.
How the Gravel Calculator Works
This gravel calculator finds the volume of the area you want to cover, adds an allowance for settling and spreading, and converts that volume to weight using the density of the material. It works for driveways, patios, walkways, drainage trenches, garden beds and the base under pavers, because each is an area filled to a set depth.
Volume answers the question "how much gravel do I need" in cubic yards, the unit most landscape yards use. Weight answers it in tons, the unit most quarries use. The two are linked only by density, which is why the same cubic yard of gravel can weigh 1.28 tons loose and 2 tons once compacted.
Depth is divided by 12 because it is measured in inches while the length and width are in feet. One cubic yard is 3 × 3 × 3 = 27 cubic feet, and a US ton (short ton) is 2,000 lb. In metric mode the depth is in centimeters and is divided by 100, the result is in cubic meters, and the weight is in metric tonnes of 1,000 kg.
How Much Does a Cubic Yard of Gravel Weigh?
Bulk density is the weight of a volume of stone including the air spaces between the pieces. The American Concrete Institute notes that the rodded bulk density of normal weight concrete aggregate generally ranges from 75 to 110 lb per cubic foot, and that well graded material with a mix of sizes packs denser than stone of one size. The calculator's material list uses these published figures:
| Material | lb per ft³ | lb per yd³ | Tons per yd³ | yd³ per ton | kg per m³ |
|---|---|---|---|---|---|
| Gravel, dry (EPA) | 100 | 2,700 | 1.35 | 0.74 | 1,602 |
| Crushed stone, size reduced (EPA) | 100 | 2,700 | 1.35 | 0.74 | 1,602 |
| Gravel, loose (EPA) | 95 | 2,565 | 1.28 | 0.78 | 1,522 |
| Gravel, wet (EPA) | 100 to 120 | 2,700 to 3,240 | 1.35 to 1.62 | 0.62 to 0.74 | 1,602 to 1,922 |
| Sand, loose (EPA) | 90.4 | 2,441 | 1.22 | 0.82 | 1,448 |
| Soil or sandy loam, loose (EPA) | 88.6 | 2,392 | 1.20 | 0.84 | 1,419 |
| Crushed stone base, compacted (Ohio DOT) | 148.1 | 4,000 | 2.00 | 0.50 | 2,373 |
The EPA figures come from its standard volume to weight conversion table. The wet gravel option in the calculator uses the top of the EPA range, 120 lb per cubic foot, so a wet load is not underestimated. The compacted figure is Ohio DOT's conversion factor for crushed stone and crushed gravel aggregate base, measured in place after compaction.
Gravel Coverage per Ton and per Cubic Yard
Coverage is volume divided by depth. One cubic yard is 27 cubic feet, and one ton of dry gravel at 100 lb per cubic foot is 20 cubic feet. The table shows the area each covers at common depths, before any extra allowance.
| Depth | yd³ per 100 ft² | ft² per yd³ | ft² per ton (dry gravel) |
|---|---|---|---|
| 2 in | 0.62 | 162 | 120 |
| 3 in | 0.93 | 108 | 80 |
| 4 in | 1.23 | 81 | 60 |
| 6 in | 1.85 | 54 | 40 |
To use the chart by hand, divide your area by the square feet per cubic yard. A 600 square foot driveway at 4 inches needs 600 ÷ 81 = 7.41 cubic yards, or 600 ÷ 60 = 10 tons of dry gravel, before the extra allowance. Adding 10 percent gives 8.15 cubic yards and 11 tons, the result of the driveway example in the calculator.
Compaction and How Much Extra to Order
The FHWA Gravel Roads Construction and Maintenance Guide warns that shrinkage from ordinary compaction is often overlooked. Placement, blading, rain and traffic settle the material, and the guide states that in many parts of the country this results in a volume reduction of 30 percent or more. Material in a stockpile or a truck is very loose, so a load that fills the area when dumped will be thinner once it settles.
There are two ways to allow for it. The first keeps the loose density and raises the extra allowance. If the volume will shrink by 30 percent, the loose volume must be the finished volume divided by 0.70, which is 1.43 times as much, or about 43 percent extra.
The second method uses a compacted density directly. Choose Compacted crushed stone base and enter the finished depth: the calculator multiplies the in place volume by Ohio DOT's 4,000 lb per cubic yard. For the same driveway that gives 11.11 × 2 = 22.22 tons, close to the first method. With the default 10 percent extra the compacted base example returns 12.22 cubic yards in place and 24.44 tons, which is about 18.11 loose cubic yards at 2,700 lb per cubic yard.
How Deep Should Gravel Be?
No building code sets the depth of a private gravel driveway or garden path, so depth is a design choice. For gravel roads, the FHWA unpaved road dust handbook says the wearing course should be at least 4 inches thick and preferably at least 6 inches, so it can hold a good crown and be maintained. The FHWA gravel roads guide adds that layers thicker than 4 inches should be placed in separate lifts to achieve good compaction and density.
Ohio DOT's aggregate base specification sets similar limits for compaction equipment. Item 304.04 allows a compacted lift of up to 8 inches with vibratory rollers heavier than 12 tons effective weight and 6 inches with 10 to 12 ton rollers, and limits lifts to 4 inches when those rollers are not used. A plate compactor or a rented walk behind roller falls in the last group, which is why the calculator suggests lifts of 4 inches or less for compacted base thicker than that.
Drainage matters as much as depth. The FHWA guide recommends a crown that rises about 1/2 inch per foot, roughly 4 percent, from the edge to the centerline, and advises against exceeding 6 percent. It also notes that base gravel and surface gravel differ: base material has larger stone and few fines so it drains, while good surface gravel needs some fine, slightly plastic material that binds into a crust.
How to Measure for Gravel
- Rectangles. Measure length and width in feet. Split an L shaped area into rectangles and add the areas.
- Circles. Measure straight across the center for the diameter. The calculator uses π × diameter² ÷ 4.
- Irregular beds. Divide into rectangles and triangles, add the areas, and use Known area.
- Depth. Measure the finished depth you want in inches, not the depth of the hole if fabric or edging takes up space.
- Existing gravel. Enter only the depth you are adding on top.
Common Mistakes
- Mixing inches and feet. 200 ft² × 3 is 600, not 50; divide the depth by 12 first.
- Dividing cubic feet by 9. A cubic yard is 27 cubic feet; 9 converts square feet to square yards.
- Using a loose density for compacted work. A compacted cubic yard holds about 1.48 times the weight of a loose dry one.
- Confusing tons and tonnes. A US ton is 2,000 lb; a metric tonne is 1,000 kg, about 2,205 lb.
- Skipping the extra. The measured volume leaves nothing for low spots.
Path, Circle and Metric Examples
Garden path with bagged gravel
At this size, bags are practical. Quikrete sells its bagged all purpose gravel, about 3/8 inch top size, in 50 lb bags, and at 100 lb per cubic foot each bag holds about 0.5 cubic feet.
Round fire pit area
Metric patio
NIST defines one cubic yard as exactly 0.764554857984 cubic meters and one pound as 0.45359237 kilograms, the factors the calculator uses to convert densities and results between unit systems.
Frequently Asked Questions
How much gravel do I need for a 10x10 area?
A 10 by 10 foot area is 100 square feet. At 3 inches deep, multiply 100 by 0.25 feet to get 25 cubic feet, then divide by 27 to get 0.926 cubic yards. Adding 10 percent for settling and spreading gives 27.5 cubic feet, or 1.02 cubic yards. At 2,700 lb per cubic yard, the EPA figure for dry gravel, that weighs 2,750 lb, or 1.38 tons, which is 55 bags of 50 lb. At 4 inches deep the same area needs 1.36 cubic yards, or 1.83 tons with the extra.
How many tons of gravel are in a cubic yard?
It depends on the stone and its moisture. The EPA's standard volume to weight conversion table lists dry gravel at 100 lb per cubic foot, which is 2,700 lb or 1.35 tons per cubic yard, and loose gravel at 2,565 lb, or 1.28 tons. Wet gravel runs 100 to 120 lb per cubic foot, up to 1.62 tons per cubic yard. Compacted crushed stone is much heavier: Ohio DOT converts aggregate base at 4,000 lb, or 2 tons, per compacted cubic yard. One ton of dry gravel fills about 0.74 cubic yards.
How much area does a ton of gravel cover?
At 100 lb per cubic foot, one ton (2,000 lb) of gravel fills 20 cubic feet. Divide that volume by the depth in feet to get the area: 20 ÷ 0.25 = 80 square feet at 3 inches deep. The same ton covers 120 square feet at 2 inches, 60 square feet at 4 inches and 40 square feet at 6 inches. One cubic yard covers 162, 108, 81 and 54 square feet at those depths. Heavier or compacted material covers less per ton, so use your supplier's density if you have it.
How do I calculate how much gravel I need?
Multiply the length by the width to get the area in square feet, or use π × diameter² ÷ 4 for a circle. Convert the depth from inches to feet by dividing by 12, then multiply by the area to get cubic feet. Divide by 27 to get cubic yards and add an allowance for settling and uneven ground. To get tons, multiply cubic yards by the weight per cubic yard, such as 2,700 lb for dry gravel, and divide by 2,000. Example: 20 × 10 ft at 3 inches is 50 cubic feet, or 2.04 cubic yards and 2.75 tons with 10 percent extra.
How deep should gravel be for a driveway?
No single code sets the depth of a private driveway. FHWA guidance for gravel roads says the gravel wearing course should be at least 4 inches thick, and preferably at least 6 inches, to hold a good crown and allow maintenance. The FHWA gravel roads guide adds that layers thicker than 4 inches should be placed in separate lifts for good compaction, with a crown of about 1/2 inch per foot. A 50 by 12 foot driveway at 6 inches compacted holds 11.11 cubic yards, about 22.22 tons at Ohio DOT's compacted factor of 4,000 lb per cubic yard, before any extra.
How many bags of gravel are in a cubic yard?
A cubic yard is 27 cubic feet, so it takes 54 bags of 0.5 cubic feet each. At 100 lb per cubic foot, a 50 lb bag holds 0.5 cubic feet, and Quikrete sells its bagged all purpose gravel in 50 lb bags. A ton of that gravel is 40 bags. Bags suit small jobs such as a path, a planter or a fire pit border. The count climbs quickly on larger areas: the 20 by 10 foot patio example at 3 inches deep needs 110 bags of 50 lb.
Sources & References
- U.S. Environmental Protection Agency. Standard Volume to Weight Conversion Factors (gravel dry, loose and wet; crushed stone; sand; soil and sandy loam; last updated 2006). epa.gov
- Ohio Department of Transportation. 2023 Construction and Material Specifications, Item 304 Aggregate Base (Section 304.07 conversion factors; Section 304.04 compacted lift limits). dot.state.oh.us
- Federal Highway Administration. Gravel Roads Construction and Maintenance Guide, FHWA 2015 (compaction shrinkage, separate lifts over 4 inches, crown, base versus surface gravel). fhwa.dot.gov
- Federal Highway Administration. Unpaved Road Dust Management: A Successful Practitioner's Handbook, Chapter 6 (wearing course thickness). fhwa.dot.gov
- American Concrete Institute. Aggregates for Concrete, Education Bulletin E1 (bulk density definition and typical range). concrete.org
- QUIKRETE. Sand and Gravel Products data sheet (All Purpose Gravel No. 1151, 50 lb bags, 3/8 inch top size). quikrete.com
- NIST. Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically (cubic yard, pound). nist.gov
Results are estimates based on the dimensions entered and the densities above. Every number on this page was recomputed with the same formulas the calculator uses. Methodology reviewed: 2026.