Gravel Calculator
Gravel is ordered by the ton but sold by the cubic yard in the yard's head, and the two only agree if you know the density. This converts your trench into both, with the compaction allowance most calculators skip.
Gravel volume and tonnage calculator
How far one ton goes
| Depth | Square feet per ton | Square feet per cubic yard |
|---|
Depth that actually works, by use
| Application | Compacted depth | Note |
|---|
Why gravel is quoted in tons and ordered in yards
Aggregate is priced per ton at the quarry because a truck is limited by weight, not volume, and then sold to homeowners either way depending on the yard. The conversion between the two is density, and density is the number nobody has when they call. Crushed stone runs about 1.40 tons per cubic yard. Pea gravel is lighter at roughly 1.35 because the rounded stones leave more void space. Riprap, which is fist-sized or larger, is lighter still at about 1.20 because the gaps between big stones are huge.
Getting this wrong by 15 percent on a 20 by 20 driveway means either a second delivery charge or a pile of stone in the side yard. Both cost more than a minute with a calculator.
How the volume is calculated
Volume in cubic feet is length times width times depth in feet, and depth in feet is inches divided by 12. A 20 by 20 pad at 4 inches is 400 square feet times 0.333 feet, which is 133.3 cubic feet. There are 27 cubic feet in a cubic yard, so that is 4.94 cubic yards. Multiply by 1.40 tons per yard and the stone weighs 6.91 tons before any allowance.
The waste allowance is not padding. Loose stone settles into soft subgrade, some spills off the truck, and the last few feet of a spread always run thin. Ten percent is the usual figure for a driveway or path. For a small decorative bed, 5 percent is enough. For anything over a dump-truck load, ask the yard whether they will deliver a partial load, because the delivery charge often costs more than the extra half ton.
Depth is the input people get wrong
Four inches of compacted crushed stone is the standard base for a residential driveway, and it needs to be four inches after compaction, not before. Loose stone compacts by roughly 20 to 25 percent, so a 5 inch loose lift becomes about 4 inches tight. If you are spreading by hand over a geotextile, add that compaction allowance on top of the waste figure rather than inside it.
A walkway needs 2 inches. A patio base under pavers is usually 4 inches of crushed stone plus 1 inch of bedding sand. Around a foundation, the gravel is a drainage layer and 6 to 12 inches is common. Riprap on a bank or outlet is measured in feet, not inches, and is placed by the truckload with an excavator.
Bagged versus bulk
Bagged gravel exists for convenience, not for area. A 0.5 cubic foot bag holds about 1/54 of a cubic yard, so this driveway would take 267 bags. At $5 a bag that is $1,300 against $342 in bulk, and 267 trips from the car. Bagged material only makes sense below about one cubic yard, or where a truck cannot reach the site.
If access is the problem, ask for a small dump trailer or a pallet of one-ton bulk bags instead. Both cost less per ton than retail bags and can be moved with a rented pallet jack or a wheelbarrow and a helper.
What the price per ton does not include
Quoted prices are usually ex-yard. Delivery for a full tandem load runs $80 to $200 depending on distance, and a short load carries a surcharge because the truck earns the same trip for less material. Ask for the delivered price and the minimum quantity, then compare that against the yard three miles further away — the closer yard is not always cheaper once the minimum is factored in.
Frequently asked questions
How many tons of gravel do I need for a 20x20 driveway?
About 7.6 tons at 4 inches deep, including a 10 percent allowance. That is 4.9 cubic yards of crushed stone at 1.40 tons per cubic yard. Order 8 tons if the yard only sells in whole tons.
How many square feet does a ton of gravel cover?
Roughly 58 square feet at 4 inches deep for crushed stone, or 116 square feet at 2 inches. One ton is about 0.71 cubic yards, and a cubic yard covers 81 square feet at 4 inches.
How many bags of gravel equal a yard?
Fifty-four 0.5 cubic foot bags make one cubic yard. Bagged gravel is roughly four times the cost per ton of bulk delivery, so it only makes sense for small areas or where a truck cannot reach.
Should I order extra gravel for compaction?
Yes, if you are spreading loose stone to a compacted depth. Loose crushed stone settles by about 20 to 25 percent, so a 5 inch loose lift finishes near 4 inches. Add that on top of the 10 percent waste allowance.
How deep should a gravel driveway be?
Four inches of compacted crushed stone over a geotextile fabric is the residential standard. Softer subgrade needs 6 inches, and heavy vehicles need a graded base rather than more stone.
What is the difference between pea gravel and crushed stone?
Pea gravel is rounded and about 1.35 tons per cubic yard; crushed stone has angular faces and runs 1.40. Angular stone locks together and stays put on a slope, which is why it is used for driveways and pea gravel is used for beds and play areas.
Does the calculator include delivery?
No. It prices material per ton. Delivery, short-load surcharges and any minimum order are separate, and they can add 20 to 40 percent to a small order.
Disclaimer: This calculator estimates volume and weight from your dimensions and a typical density for the material selected. Actual density varies with moisture and gradation, and compacted depth differs from loose depth. Confirm tonnage with your supplier before ordering.
Citing this page? FigureMill, “Gravel Calculator” (last reviewed October 31, 2026). Gravel volume in cubic yards and tons from length, width and depth, with a compaction and waste allowance and a per-ton cost. https://figuremill.com/materials/gravel-calculator
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