Gravel Calculator

How to use this calculator

Measure the length and width of the area you're covering and decide how deep the gravel needs to be. Enter those three numbers and you'll get the weight in tons — the unit gravel is almost always sold and delivered in — along with cubic yards, cubic feet, and bags if you're buying small quantities. Covering several areas, or a driveway plus a path? Add a row for each and they're totaled together.

Two optional fields matter. Density defaults to 1.4 tons per cubic yard, which suits typical gravel; drop it to about 1.3 for dry pea gravel or raise it to 1.5 or more for crushed stone. Bag size is only relevant if you're buying bagged gravel rather than bulk — leave it blank otherwise.

The formula, explained

Gravel is a two-step calculation: work out the volume, then convert that volume to weight, because the volume is what fills your space but the weight is what you order.

Length (ft) × Width (ft) × (Depth in ÷ 12) = cubic feet
Cubic feet ÷ 27 = cubic yards
Cubic yards × density = tons

The 27 comes from a cubic yard being 3 ft × 3 ft × 3 ft. Density is the step people skip — gravel isn't sold by volume at the quarry, it's weighed on a truck scale, so you need the conversion to order correctly.

Worked example: a 30 ft × 10 ft driveway at 4 inches

1. Area: 30 × 10 = 300 square feet
2. Convert the depth: 4 ÷ 12 = 0.333 ft
3. Volume: 300 × 0.333 = 100 cubic feet
4. Cubic yards: 100 ÷ 27 = 3.70 cubic yards
5. Tons: 3.70 × 1.4 = 5.19 tons
6. Add 10% for compaction and waste: about 5.7 tons

That last step matters more for gravel than for most materials. Gravel is delivered loose and then compacted, and it loses volume as it tightens — so the loose yardage you order is not the compacted depth you end up with.

How deep should gravel be?

Depth is driven by what sits on top and what the ground underneath is like. Poor-draining clay soil generally needs a deeper base than firm, well-drained ground.

Use	Typical depth	Notes
Decorative beds & borders	2–3 inches	Over landscape fabric
Garden paths & walkways	2–3 inches	Over fabric, edged to hold it in
Concrete slab base	4 inches	Compacted, angular stone
Paver patio base	4–6 inches	Plus 1 in bedding sand on top
Driveway (cars, firm soil)	4–6 inches	Compacted in lifts
Driveway (clay, heavy vehicles)	6–8 inches	Compacted in 3–4 in lifts
French drain trench	12+ inches	Clean stone, no fines

Our guide on gravel under a concrete slab goes deeper on base preparation and why the layer matters.

How much area does a ton of gravel cover?

A useful sanity check when a supplier quotes you by the ton. At 1.4 tons per cubic yard, one ton is about 19.3 cubic feet of loose gravel:

Depth	Coverage per ton
2 inches	about 116 sq ft
3 inches	about 77 sq ft
4 inches	about 58 sq ft
6 inches	about 39 sq ft

How much gravel for common project sizes

Figures below use the default 1.4 tons per cubic yard and include no waste allowance — add 5–10% to whatever you order.

Project	Size & depth	Cubic yards	Tons
Decorative bed	10 × 10 ft @ 2 in	0.62	0.86
Garden path	3 × 20 ft @ 3 in	0.56	0.78
Patio base	10 × 10 ft @ 4 in	1.23	1.73
Shed pad base	10 × 12 ft @ 4 in	1.48	2.07
Driveway (1 car)	10 × 20 ft @ 4 in	2.47	3.46
Patio base (large)	12 × 20 ft @ 4 in	2.96	4.15
Slab base	20 × 20 ft @ 4 in	4.94	6.91
Driveway (2 car)	12 × 24 ft @ 6 in	5.33	7.47
Driveway (long)	12 × 50 ft @ 6 in	11.11	15.56

Step by step: how to measure your area

1. Measure the finished footprint, not the excavation. Measure length and width in two or three places and use the largest reading if they differ.
2. Split odd shapes into rectangles. A driveway with a parking apron is two rectangles. Enter each as its own row rather than averaging them into one.
3. Measure depth from the finished grade down to the compacted subgrade, at several points. Ground is rarely level, and the deep corner is what runs you short.
4. For a curved or circular area, use π × radius² for the square footage and enter it as a rectangle with the same area — for example, a 10 ft circle is about 79 sq ft, so enter 10 × 7.9.
5. Add your waste allowance last, once the total is known.

Choosing the right gravel

This is where most gravel projects go wrong, and it has nothing to do with quantity. The single most important distinction is angular vs. rounded. Angular stone has jagged faces that lock together under compaction and stay put. Rounded stone rolls past itself under load and never firms up, no matter how much you compact it.

Type	What it is	Use it for
Crusher run (road base, QP)	Angular stone plus fines	Bases under slabs, pavers, driveways
#57 stone	Clean ¾ in angular, no fines	Drainage layers, French drains
Pea gravel	Small, smooth, rounded	Paths, decorative areas — never bases
River rock	Large, smooth, rounded	Decorative beds, dry creek beds
Stone dust / screenings	Fine crushed material	Levelling course, joint filling

The fines in crusher run are what make it compact into a solid, load-bearing layer — they fill the gaps between the larger stones. Clean stone like #57 has no fines by design, which is exactly what you want for drainage and exactly what you don't want under a slab.

Why density matters

Because you order by weight, density changes your bill. The same 3.70 cubic yard hole takes:

Material	Density	Tons needed
Pea gravel (dry)	1.3 t/cu yd	4.81
Typical gravel	1.4 t/cu yd	5.19
Crushed stone	1.5 t/cu yd	5.56
Wet or dense stone	1.7 t/cu yd	6.30

That's a 30% swing between the lightest and heaviest. If your supplier gives you a density figure for the specific material you're buying, use it in the density field — it's more accurate than any default.

What will it cost?

Gravel is cheap by the ton and expensive to move, so delivery is often a large share of a small order. Typical planning ranges:

• Crusher run / road base: roughly $20–$30 per ton
• Clean stone (#57): roughly $30–$45 per ton
• Pea gravel & decorative: roughly $35–$60 per ton
• Delivery: $50–$150 locally, often with a minimum load

Worked cost: a 12 × 24 ft driveway base at 6 inches

That's 5.33 cubic yards, or 7.47 tons — about 8.2 tons with 10% added.

• Material: 8.2 tons × $20–$45 = $164–$370
• Delivery: $50–$150
• Total: roughly $214–$520

Because delivery is close to fixed, ordering one load of 8 tons is far cheaper per ton than two loads of 4. If you have a second gravel job coming, it's usually worth doing both at once.

Common gravel mistakes

• Using pea gravel as a base. Rounded stone will not compact and never stops shifting. Anything load-bearing needs angular crushed stone.
• Forgetting compaction loss. Loose gravel tightens as it's compacted. Order for the loose volume and add 5–10%, or your finished depth will come up short.
• Dumping the full depth in one go. A plate compactor can only compact about 4 inches at a time. Deeper bases go down in lifts, each one compacted before the next.
• Mixing up inches and feet. A 4-inch depth is 0.333 ft, not 4. The calculator handles the conversion — just check your unit toggle.
• Using clean stone under a slab. #57 has no fines, so it won't lock into a firm, level surface. Use crusher run for bases and save clean stone for drainage.
• Skipping the fabric on decorative gravel. Without landscape fabric underneath, decorative gravel sinks into the soil and weeds come straight through.

Pro tips for a base that lasts

• Ask your supplier for the density of the exact material you're buying, then enter it in the density field. Quarry figures beat generic defaults.
• Compact in lifts of 3–4 inches. Run the plate compactor over each lift until the stone stops moving under the plate.
• Check compaction by walking it. If you leave visible footprints, it isn't compacted yet.
• Dampen dusty stone before compacting. A light spray helps the fines settle in and bind — but don't soak it.
• Slope it away from buildings. Roughly a quarter inch of fall per foot keeps water moving off the base rather than sitting under it.
• Order one big load, not two small ones. Delivery is close to fixed cost, so combining jobs saves real money.

A note on accuracy

This calculator gives you a clean figure from your measurements and the density you choose. Real deliveries vary with moisture content, how tightly the material is compacted, and how level your subgrade is, so treat the result as a close planning number and round up when ordering. Suppliers usually have a minimum load, so it's worth a quick call before you book.

Where these figures come from

The base depth guidance built into this calculator comes from the published sources below. The arithmetic itself — converting measurements to volume, and volume to bags or tons — is straightforward unit conversion, and you can check it in the full working the calculator shows. Material densities and bag yields vary by product and supplier, so confirm the figure printed on the bag or quoted by your yard before you order.

• Subgrades and Subbases for Concrete Pavements (EB204P, PDF) Source: American Concrete Pavement Association / Portland Cement Association. Base and subbase material selection, depth, and compaction.
• Bases and Subbases for Concrete Pavement (Tech Brief, PDF) Source: U.S. Federal Highway Administration. A government overview of base and subbase design.
• Concrete Materials and Properties (Chapter 4, PDF) Source: Wisconsin Department of Agriculture, Trade and Consumer Protection. Explains the 4-inch compacted base convention.

Frequently asked questions

How much gravel do I need for a 10x10 patio base?

A 10 ft by 10 ft area at 4 inches deep needs about 33.3 cubic feet — roughly 1.23 cubic yards, or about 1.73 tons at typical gravel density. Add 5–10% for compaction and waste, which brings it to about 1.9 tons.

How many tons of gravel are in a cubic yard?

About 1.4 tons for typical gravel. Dry pea gravel runs closer to 1.3 tons per cubic yard, crushed stone around 1.5, and wet or especially dense stone up to about 1.7. If your supplier gives you a figure for the exact material, use that in the density field.

How much area does a ton of gravel cover?

At typical density, one ton is about 19.3 cubic feet of loose gravel. That covers roughly 116 sq ft at 2 inches deep, 77 sq ft at 3 inches, 58 sq ft at 4 inches, or 39 sq ft at 6 inches.

How deep should a gravel driveway be?

Four to six inches of compacted angular stone over firm, well-drained soil. On clay, poor-draining ground, or where heavy vehicles park, go to 6–8 inches. Either way, put it down and compact it in 3–4 inch lifts rather than all at once.

Can I use pea gravel as a base under pavers or concrete?

No. Pea gravel is smooth and rounded, so it rolls past itself under load and never compacts into a stable layer. Bases need angular crushed stone such as crusher run, where the jagged faces lock together and the fines fill the gaps. Save pea gravel for paths and decorative areas.

How much extra gravel should I order?

Add 5–10%. Gravel is delivered loose and loses volume when compacted, so ordering the exact calculated figure leaves you short of your target depth. Use the higher end for deeper bases and uneven subgrade.

What's the difference between crusher run and #57 stone?

Crusher run is angular stone mixed with fine material, so it compacts into a solid, load-bearing base. #57 stone is clean ¾ inch angular stone with the fines washed out, so water runs straight through it. Use crusher run under slabs and pavers; use #57 for French drains and drainage layers.

How much does gravel cost?

Crusher run runs roughly $20–$30 per ton, clean stone $30–$45, and decorative gravel $35–$60. Delivery adds $50–$150 locally and is close to a fixed cost, so one large load is much cheaper per ton than two small ones. Prices vary by region and haul distance.