Gravel Calculator
Ask for a yard of gravel and you might get 2,700 lb or 3,000 lb, depending entirely on which grade turns up. This gravel calculator uses the density of the stone you are actually buying, so the tonnage it gives you is the tonnage the quarry will weigh out.
Your result
What to order
NaN tons of #57 stone (3 cu yd) for 240 sq ft at 4 in
About $158 at $38 a ton, or $0.66 a square foot. Bulk beats bags above roughly half a cubic yard, which is 27 bags.
- Coverage at this depth
- One ton of #57 stone covers about 58 sq ft at 4 in. A cubic yard weighs 2,800 lb, so it is 1.4 tons to the yard and 0.71 yards to the ton.
- Grade changes the tonnage
- The same 3 cubic yards is 4.1 tons of #57 stone but 4.4 tons of crusher run and 4 tons of pea gravel. Order by volume and confirm the weight, or the other way round.
- How this is worked out
- 240 sq ft × 4 in ÷ 12 ÷ 27 = 2.96 cu yd × 2,800 lb ÷ 2,000 = 4.15 tons
How much gravel do you need
Area times depth, converted to cubic yards, then multiplied by the weight of your grade. Measure the area in square feet, multiply by the depth in inches, divide by 12 to get cubic feet and by 27 to get cubic yards.
A 20 by 12 ft parking pad is 240 sq ft. At 4 in that is 2.96 cubic yards, which comes to 4.1 tons in #57 stone, 4.4 tons in crusher run or 4 tons in pea gravel. Same hole, three different orders.
The shortcut worth learning is dividing by 324. A cubic yard spread one inch deep covers 324 sq ft, so square feet times inches divided by 324 gives cubic yards directly. It folds both conversions into one step and it works for any material.
Gravel coverage, and how much a yard covers
One cubic yard covers 324 sq ft at 1 in, 162 sq ft at 2 in, 108 sq ft at 3 in and 81 sq ft at 4 in. That column never changes, whatever the stone, because it is pure geometry rather than weight.
| Depth | Sq ft per cubic yard | Sq ft per ton | Typical use |
|---|---|---|---|
| 1" | 324 | 231 | Light top dressing over existing stone |
| 2" | 162 | 116 | Refreshing an existing surface or a decorative bed |
| 3" | 108 | 77 | Foot traffic over a firm subgrade |
| 4" | 81 | 58 | Vehicles, over a compacted base course |
| 6" | 54 | 39 | Structural base under a drive or slab |
Coverage per ton does move with the grade, because a ton of light stone is more cubic yards than a ton of heavy stone. A ton of pea gravel covers 80 sq ft at 3 in against 72 sq ft for crusher run, a difference of about 11%.
Coverage halves every time depth doubles, which is the trap on large areas. Adding an inch to a 1,000 sq ft drive is not a rounding adjustment, it’s another 4.3 tons and most of another delivery.
Gravel weight and tons per yard
Gravel runs between 2,700 and 3,000 lb per cubic yard. That spread is about 11%, which is far too much to ignore on anything bigger than a wheelbarrow.
| Grade | Size | Lb per yd³ | Tons per yd³ | $/ton |
|---|---|---|---|---|
| #57 stone | 3/4" | 2,800 | 1.40 | $38 |
| 3/4" clean | 3/4" | 2,800 | 1.40 | $40 |
| #8 stone | 3/8" | 2,750 | 1.38 | $42 |
| #4 stone | 1–1.5" | 2,750 | 1.38 | $36 |
| Crusher run | 3/4" minus | 3,000 | 1.50 | $32 |
| Pea gravel | 3/8" | 2,700 | 1.35 | $45 |
| River rock | 1–3" | 2,700 | 1.35 | $65 |
| Decomposed granite | Fines | 3,000 | 1.50 | $45 |
Crusher run is heaviest because the dust fills the gaps between the stones, so there is less air in a yard of it. Rounded stone like pea gravel and river rock is lightest, since spheres can’t pack as tightly as angular pieces. Everything else sits between the two.
The 1.5 tons per yard rule of thumb is within about 10% for every grade here, which makes it fine for checking that an order is roughly right and not good enough to order from.
Weight also decides what a truck can legally carry. A tandem dump rated at 14 tons holds about 9.3 cubic yards of crusher run but nearer 10.4 of pea gravel, so a load is a different volume depending on the grade. Order by volume on a tight site and you can end up paying for a second delivery you did not plan for.
How many bags of gravel in a yard
54 bags, at the half cubic foot size most garden centers sell. A cubic yard is 27 cubic feet, so the arithmetic is 27 divided by the bag size.
| Bag size | Bags per cubic yard | Bags for 2.96 yd³ |
|---|---|---|
| 0.5 cu ft | 54 | 160 |
| 0.75 cu ft | 36 | 107 |
| 1 cu ft | 27 | 80 |
Bagged stone runs three to five times the bulk price per yard once you account for the packaging. The crossover is around half a cubic yard, or 27 bags, at which point a bulk delivery is cheaper even after the haulage charge.
Bags still win for small patches, awkward access and anywhere a truck can’t tip. Carrying 160 bags through a house to a back garden is a genuine reason to pay the premium, and so is not having a pile of stone sitting on the drive for a week.
Watch the units on the bag as well. Stone is sometimes sold by weight rather than volume, and a 50 lb bag of crusher run is only about 0.45 cubic feet. Comparing a weight-labeled bag against a volume-labeled one without converting is how people end up a third short on a small job and make a second trip for it.
Gravel sizes and grades explained
Grade numbers describe the size of the screened stone. Lower numbers are bigger, which is the opposite of what most people assume, and the letter or word after the number tells you whether the fines are still in it.
| Grade | Size | Shape | What it is for |
|---|---|---|---|
| #57 stone | 3/4" | Angular | Driveways, drainage, concrete mix. The most stocked grade there is |
| 3/4" clean | 3/4" | Angular | Washed and screened, so it drains. Same size as #57 without the fines |
| #8 stone | 3/8" | Angular | Paths, paver bedding and top dressing over larger stone |
| #4 stone | 1–1.5" | Angular | Base course under drives, erosion control, soft ground |
| Crusher run | 3/4" minus | Angular | Dust left in so it packs hard. Driveway surfaces and compacted base |
| Pea gravel | 3/8" | Rounded | Rounded and smooth. Play areas, patios, anywhere bare feet go |
| River rock | 1–3" | Rounded | Decorative beds, dry creek beds, drainage where it shows |
| Decomposed granite | Fines | Angular | Paths and seating areas that need a firm walking surface |
3/4 gravel and #57
Both are 3/4 in stone and they are close to interchangeable. #57 is the graded spec, washed clean of fines, and it is what a supplier will reach for if you ask for three quarter inch gravel. It drains, it compacts enough to walk on and it is stocked everywhere.
Clean stone against minus
Clean stone has been washed, so water runs straight through it. Minus grades like crusher run keep the stone dust, which lets them pack into a hard surface but also stops them draining. Use clean where water has to move and minus where the surface has to be firm.
Rounded against angular
Angular stone locks together and stays put on a slope. Rounded stone like pea gravel rolls under a tire and migrates downhill, which is why it belongs on patios and play areas rather than driveways. It’s also the only kind that is comfortable to walk on barefoot.
Gravel as a mulch and ground cover
Gravel mulch does the same job as bark, without breaking down. It suppresses weeds, holds moisture in the soil and never needs topping up on an annual cycle, which is why it has largely replaced bark in hot and dry regions.
Two inches is enough over landscape fabric and three inches without it. Any less and light reaches the soil and weeds come through; any more and it becomes hard to plant into. A 240 sq ft bed at 2 in takes 1.48 cubic yards, which in river rock is about 2 tons.
The trade against bark is permanence. Gravel doesn’t feed the soil and it is hard work to remove once it has worked its way into the top few inches, so it suits planting schemes you intend to keep. On slopes and paths, binding products sold as mulch glue will lock loose stone in place, though they need reapplying and they make future planting awkward.
What gravel costs
Between $32 and $65 a ton delivered, with crusher run at the bottom and decorative river rock at the top. Per cubic yard that is roughly $48 to $88.
Delivery is charged per load rather than per ton, usually $75 to $150 within a normal radius, which is why one larger order almost always beats two small ones. A tandem dump carries about 14 tons, so ordering 15 buys a second trip for one ton of stone.
Prices move sharply with distance from the quarry because stone is heavy and travels badly. A yard twenty miles away can be cheaper delivered than one sixty miles away is to collect, so it pays to ring two or three and ask for the delivered price rather than the pickup rate.
Gravel questions
How much gravel do I need?
Multiply the area in square feet by the depth in inches, divide by 12 then by 27 for cubic yards. A 240 sq ft pad at 4 in is 2.96 cubic yards, which in #57 stone is about 4.1 tons. Multiply cubic yards by the grade's weight per yard to get tons.
How many tons of gravel are in a cubic yard?
Between 1.35 and 1.5 tons depending on the grade. #57 stone is 1.4 tons per cubic yard, crusher run 1.5 and pea gravel 1.35. The rule of thumb of 1.5 tons a yard is close enough to sanity-check an order.
How to calculate cubic yards of gravel?
Square feet times depth in inches, divided by 324. That single number folds in both conversions, because a cubic yard spread one inch deep covers 324 sq ft. For 240 sq ft at 4 in that gives 2.96 cubic yards.
How many bags of gravel are in a yard?
54 bags at half a cubic foot each, since a cubic yard is 27 cubic feet. At 0.5 cu ft a bag that is 54 bags, and bagged stone costs several times the bulk price, so bulk wins above about half a yard.
What size gravel should I use?
#57 at 3/4 in for drives and drainage, #8 at 3/8 in for paths and paver bedding, crusher run where it needs to pack hard, and pea gravel only where bare feet go. Size matters less than whether the fines have been washed out.
What is 57 gravel used for?
Driveways, drainage trenches, under concrete slabs and as a middle course in a layered drive. It’s 3/4 in washed angular stone with the fines removed, so it locks together but still lets water through. It’s the most commonly stocked grade in the country.
How much does a yard of gravel cost?
Roughly $48 to $88 a cubic yard delivered, depending on the grade. Crusher run is cheapest and decorative river rock the dearest. Delivery adds $75 to $150 a load whatever the tonnage.
Should I order gravel by the yard or by the ton?
Whichever your supplier quotes in, but confirm which one before comparing prices. A yard priced against a ton looks about a third cheaper than it is. Quarries usually sell by weight and load by volume, so both units come up in the same call.