Gravel Calculator for Driveways, Paths and Beds
Ask for a yard of gravel and you might get 2,700 lb. Or you might get 3,000 lb. It depends entirely on which grade turns up on the truck. This gravel calculator uses the density of the stone you’re actually buying, so the tonnage it gives you is the tonnage the quarry weighs 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
What is gravel?
Gravel is crushed or screened stone, sorted into grades by size. The grade number tells you how big the pieces are, and whether the fines have been washed out. Clean stone drains. Stone with the dust left in packs hard. That single difference decides whether it belongs in a drain or under a driveway.
So why work the tonnage out first? Because gravel is sold by weight, planned by area, and delivered by the yard. Three units for one pile. A quote in one tells you very little about a quote in another.
And here's what makes gravel different from everything else on this site. Every grade weighs something different. Pea gravel and crusher run are hundreds of pounds apart per cubic yard. Use one average figure and you can be a ton out on a normal driveway.
How much gravel do you need
Three steps. Area times depth, converted to cubic yards, then multiplied by your grade’s weight. So: square feet × depth in inches ÷ 12 ÷ 27 = cubic yards.
A 20 by 12 ft parking pad is 240 sq ft. At 4 in that’s 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.
There’s a shortcut worth learning here. Divide by 324. A cubic yard spread one inch deep covers 324 sq ft, so square feet times inches divided by 324 gives you cubic yards in one step. Works for any material, not just gravel.
Gravel coverage, and how much a yard covers
One cubic yard covers 324 sq ft at 1 in. At 2 in it does 162, at 3 in it does 108, and at 4 in it does 81. Those numbers hold whatever stone you buy, because this is geometry, not 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 is a different story. A ton of light stone gives you 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%.
Watch what happens on big areas though. Double the depth and one yard does half the ground. Adding an inch to a 1,000 sq ft drive is not a small tweak. 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 is a spread of about 11%. 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 |
Why is crusher run heaviest? 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 comes out lightest, because spheres cannot pack as tightly as angular pieces. Everything else sits somewhere between the two.
The old 1.5 tons per yard rule sits within about 10% for every grade here. Fine for checking an order looks roughly right. Not good enough to actually order from.
Weight decides what a truck can legally carry too. A tandem dump rated at 14 tons holds about 9.3 cubic yards of crusher run. In pea gravel it holds nearer 10.4. Same truck, different volume, purely from the grade. Order by volume on a tight site and you can end up paying for a second delivery you never planned 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 costs three to five times the bulk price per yard once the packaging is in there. The crossover comes at around half a cubic yard, or 27 bags. Past that, bulk delivery wins even after haulage.
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 real reason to pay the premium. So is not having a pile of stone sat on your drive for a week.
Check the units on the bag, too. 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 tell you the size of the screened stone. Here’s the confusing part: lower numbers mean bigger stone, which is the opposite of what most people assume. 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’re close to interchangeable. #57 is the graded spec, washed clean of fines, and it’s what a supplier will reach for if you ask for three quarter inch gravel. It drains, it compacts enough to walk on and it’s 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’s comfortable to walk on barefoot.
Gravel as a mulch and ground cover
Gravel mulch does the same job as bark, except it never breaks down. It keeps weeds down, holds moisture in the soil, and you never top it up every year. That’s why it has mostly replaced bark in hot, 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 once it works its way into the top few inches, getting it out is hard work. So it suits planting you mean to keep. On slopes and paths, binding products sold as mulch glue lock loose stone in place. They need reapplying though, 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’s roughly $48 to $88.
Delivery gets charged per load rather than per ton, usually $75 to $150 inside a normal radius. Which is why one bigger order almost always beats two small ones. A tandem dump carries about 14 tons, so ordering 15 buys you a whole second trip for one ton of stone.
Prices move sharply with distance, because stone is heavy and travels badly. A yard twenty miles away can beat one sixty miles away, even delivered against collected. So call two or three and ask for the delivered price, not the pickup rate.
Gravel questions
How much gravel do I need?
Multiply the area in square feet by the depth in inches, then divide by 12 and by 27. That gives cubic yards. A 240 sq ft pad at 4 in comes to 2.96 cubic yards, which in #57 stone is about 4.1 tons. For tons, multiply cubic yards by your grade's weight per yard.
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 is 1.5, pea gravel 1.35. The old rule of 1.5 tons a yard is close enough to check an order against.
How to calculate cubic yards of gravel?
Square feet times depth in inches, divided by 324. That one number handles both conversions, because a cubic yard spread an inch deep covers 324 sq ft. For 240 sq ft at 4 in, you get 2.96 cubic yards.
How many bags of gravel are in a yard?
54 bags at half a cubic foot each, because a cubic yard is 27 cubic feet. Bagged stone costs several times the bulk price, so bulk wins on anything above about half a yard.
What size gravel should I use?
Use #57 at 3/4 in for drives and drainage. Use #8 at 3/8 in for paths and paver bedding. Crusher run goes where it has to pack hard, and pea gravel only where bare feet go. Honestly, 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 the middle course in a layered drive. It’s 3/4 in washed angular stone with the fines taken out, so it locks together but still lets water through. It’s the most widely 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. Just confirm which one before you compare prices. A yard priced against a ton looks about a third cheaper than it really is. Quarries sell by weight and load by volume, so both units come up in the same phone call.