Gravel Calculator

Work out how much gravel you need before you order it. Enter the size of your area and how deep you want the gravel, and this calculator tells you the volume, the weight, how many 50 lb bags that is, and roughly what it will cost. No sign-up. No math. It works in feet and inches or in meters and centimeters.

How much gravel do you need?

• One cubic yard of gravel covers about 162 sq ft at 2 inches deep, 108 sq ft at 3 inches, 81 sq ft at 4 inches, or 54 sq ft at 6 inches.
• One cubic yard weighs roughly 1.4 US tons (about 2,835 lb) for standard dry gravel.
• One ton of gravel covers about 100 sq ft at 2 inches deep, or 50 sq ft at 4 inches deep.
• A 50 lb bag holds about 0.5 cubic feet, so you need around 54 bags per cubic yard.

Your own number depends on the exact area, the depth and the type of stone, so run it through the calculator above for a figure you can hand to your supplier.

How to use the gravel calculator

1. Choose your unit system. Tap Imperial for feet and inches or Metric for meters and centimeters. Every field switches over for you.
2. Pick the shape of your area.
   • Rectangle: enter length and width. Best for driveways, paths and patios.
   • Circle: enter the diameter. Best for fire pits, round beds and tree rings.
   • Custom area: already know your square footage? Type it straight in.
3. Enter the depth. This is how thick you want the finished gravel layer. Inches, feet, yards, centimeters, millimeters and meters are all accepted.
4. Choose your gravel type. Each option carries its own density, so the weight is realistic instead of generic. If your supplier gave you a density, choose Custom Density and enter it in kg/m³ or lb/ft³.
5. Set the waste buffer. Slide it from 0% to 30%. Around 10% is a sensible default for spillage, settling and uneven ground.
6. Press Calculate. You get your area, depth, volume, weight, bag count and metric tonnes in one place.
7. Open the cost box (optional). Enter the price your supplier quoted, per US ton, per tonne, per cubic yard, per cubic meter, per cubic foot or per kilogram, and you will see the estimated total.

What the results mean

Result	What it tells you
Area covered	The surface you are filling, shown in both square feet and square yards (or m² and ft² in metric)
Depth	Your gravel layer thickness, shown in inches and centimetres
Volume needed	The main figure for buying in bulk; cubic yards or cubic meters, waste already included
Volume (alt)	The same volume in a second unit, handy when a supplier prices by the cubic foot
Weight needed	What the load actually weighs, in US tons or kilograms; useful for delivery limits
50 lb bags	How many standard bags to buy if you are shopping at a hardware store
Tonnes	Metric tonnes, for suppliers who quote that way

The volume and weight both include your waste buffer, so the number on screen is the number to order.

The formula behind it

The gravel calculator does three simple steps.

Step 1: Find the area

Rectangle: Area = Length × Width
Circle: Area = π × (Diameter ÷ 2)²
Custom: Area = the value you type in

Step 2: Turn area into volume

Volume = Area × Depth × (1 + Waste %)

Step 3: Turn volume into weight

Weight = Volume × Density of your gravel

Everything is converted to meters and kilograms behind the scenes, then shown back to you in the units you chose. That is why mixing units, length in feet, depth in inches, still gives a correct answer.

Worked example

A driveway 30 ft long and 12 ft wide, 4 inches deep, in standard dry gravel, with a 10% buffer:

• Area = 30 × 12 = 360 sq ft
• Depth = 4 in = 0.333 ft
• Volume = 360 × 0.333 = 120 cu ft = 4.44 cu yd
• Plus 10% waste = 4.9 cubic yards
• Weight = about 6.9 US tons

So you would order 5 cubic yards, or roughly 7 tons.

Gravel types and their weights

Density is why two loads of the same size can weigh very differently. These are the values built into the calculator.

Gravel type	Density (lb/ft³)	Density (kg/m³)	Best for
Regular gravel: dry	105	1,682	General landscaping and paths
Regular gravel: wet	125	2,002	Same stone after rain, or damp storage
Pea gravel	112	1,788	Playgrounds, patios, walkways, pool edges
Crushed stone / limestone	100	1,602	Driveways, base layers, drainage
Road base / compacted gravel	115	1,842	Sub-base under driveways and slabs
Gravel & sand: dry	103	1,650	Backfill and levelling
Gravel & sand: wet	119	1,905	Damp backfill
Gravel & clay: dry	105	1,680	Compacted farm and access tracks
Decomposed granite	120	1,923	Paths, xeriscape beds, patios
Lava rock / pumice	55	880	Lightweight mulch and planting beds
Marble chips	85	1,362	Decorative borders and beds
Fine gravel: pea-sized	95	1,520	Topping layers and narrow paths

Wet gravel can weigh 10–20% more than dry gravel. If rain is forecast before delivery, or the stone is stored outside, pick the wet option so your weight and cost are not understated.

How deep should the gravel be?

Project	Recommended depth	Notes
Walkways and garden paths	2–3 in (5–8 cm)	Use smaller stone so it stays comfortable to walk on
Patios and seating areas	2–3 in (5–8 cm)	Compact firmly and edge it to stop spread
Flower beds and decorative mulch	2–3 in (5–8 cm)	Enough to hold moisture and block weeds
Car driveway	4–6 in (10–15 cm)	Often two layers: coarse base, finer top
Heavy or commercial driveway	8–12 in (20–30 cm)	Build up in layers and compact each one
Drainage trench or French drain	12–18 in (30–45 cm)	Use clean, angular stone
Shed or slab sub-base	4–6 in (10–15 cm)	Compacted road base works best

If you are building layers, run the calculator once per layer and add the results together.

Coverage at a glance

One cubic yard of gravel covers:

Depth	Area covered
1 in	324 sq ft
2 in	162 sq ft
3 in	108 sq ft
4 in	81 sq ft
6 in	54 sq ft
12 in	27 sq ft

One US ton of standard gravel covers:

Depth	Area covered
2 in	about 114 sq ft
3 in	about 76 sq ft
4 in	about 57 sq ft
6 in	about 38 sq ft

One cubic meter of gravel covers:

Depth	Area covered
5 cm	20 m²
8 cm	12.5 m²
10 cm	10 m²
15 cm	6.7 m²

Bags or bulk delivery?

• Under about 0.5 cubic yards: bags usually win. That is roughly 27 bags of 50 lb, and you can carry them in a car.
• Half a yard to a full yard: compare the two. Bags cost more per unit but avoid delivery fees.
• More than one cubic yard: order bulk. Once you are past about 54 bags, loose delivery is cheaper and far less lifting.

Remember that most pickup trucks safely carry about 1 cubic yard of gravel. A full yard can weigh close to 1.5 tons, which is more than many half-ton trucks should take.

How much does gravel cost?

Prices change by region and by stone, but as a rough guide:

Type	Typical price
Crushed stone / limestone	$25–$60 per ton
Regular gravel	$30–$70 per ton
Pea gravel	$35–$75 per ton
Decomposed granite	$40–$90 per ton
Marble chips	$80–$180 per ton
Lava rock	$100–$250 per ton

Delivery is usually charged separately, often $60–$150 per load depending on distance. Enter your supplier’s quoted price in the cost box and the calculator applies it to your exact volume or weight, including the waste buffer.

Tips before you order

• Measure twice. A one-foot error on a long driveway can change your order by a whole ton.
• Round up, not down. Reordering a small top-up costs far more per unit than buying a little extra up front.
• Keep the 10% buffer. Gravel settles, spreads into soil and gets lost in low spots.
• Add a base layer for driveways. A coarse base under a finer top layer lasts much longer than one thick layer of the same stone.
• Edge the area. Timber, steel or plastic edging keeps gravel where you put it and reduces top-ups later.
• Lay landscape fabric. It blocks weeds and stops stone sinking into soft ground.
• Check access. Tell your supplier where the truck can tip, and whether there are gates, low branches or soft lawn in the way.

Frequently asked questions (FAQs)

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References

• ASTM International. C29/C29M — Standard Test Method for Bulk Density (“Unit Weight”) and Voids in Aggregate.
• AASHTO. M 147 — Standard Specification for Materials for Aggregate and Soil-Aggregate Subbase, Base, and Surface Courses.
• U.S. Environmental Protection Agency. Gravel Roads: Maintenance and Design Manual.
• U.S. Geological Survey. Aggregates Statistics and Information (crushed stone, construction sand and gravel).

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Technical Basis

This calculator uses standard volume and density equations from construction practice. Bulk density follows the basis of ASTM C29/C29M, with values in the ranges commonly reported for gravel and crushed stone. Aggregate sizes and depth guidance reference ASTM D448, AASHTO M147 and the FHWA Gravel Roads Construction and Maintenance Guide. Price ranges reflect USGS aggregate data.

Disclaimer

This tool provides estimates based on standard formulas and reference data. Actual requirements may vary depending on local codes, material variations, and project conditions. For final design decisions, consult a licensed professional.

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