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Gravel Calculator

Calculate exactly how much gravel you need for driveways, walkways, patios, and landscaping. Get instant volume, weight, and cost estimates.

100% FreeInstant ResultsCost Estimator
Gravel Calculator
Enter your project dimensions to calculate volume, weight, and cost
Enter to calculate, Esc to clear

Density: 100 lb/ft³ (1600 kg/m³)

Local prices: $30-75/yard typical

Try These Common Projects
Click on any example to automatically fill the calculator with typical values
Standard Driveway

50×12 ft driveway with crushed stone base

📐 50×12 ft
📏 4" deep • $45/yard
🪨 Crushed Stone (#57)
Garden Walkway

30×4 ft path with decorative pea gravel

📐 30×4 ft
📏 2" deep • $35/yard
🪨 Pea Gravel
Fire Pit Area

8 ft radius circle with river rock

8 ft radius
📏 3" deep • $55/yard
🪨 River Rock
Patio Base

20×20 ft patio with decomposed granite

📐 20×20 ft
📏 4" deep • $40/yard
🪨 Decomposed Granite
How to Use the Gravel Calculator

Step-by-step guide:

  1. Select the area shape (total area, rectangle, circle)
  2. Enter dimensions (length/width/radius or total area)
  3. Set gravel depth
  4. Choose gravel type (affects density)
  5. (Optional) Enter price to calculate cost
  6. Click "Calculate"

Pro Tip: Always add 5-10% extra for spillage and uneven surfaces.

Gravel Calculation Basics

Key Formulas:

  • Volume: Area × Depth
  • Weight: Volume × Density
  • Cost: Volume × Price (or Weight × Price per ton)

Unit Conversion:
3 inches = 3 ÷ 12 = 0.25 feet
10 cm = 10 ÷ 100 = 0.1 meters

Recommended Gravel Depths for Projects
Project TypeRecommended DepthNotes
Driveway4–6 inchesHeavy traffic, use crushed stone
Garden Path2–3 inchesLight traffic, pea gravel works well
French Drain6–12 inchesDrainage layer, use clean gravel
Landscaping Bed2–4 inchesDecorative, various types suitable
Gravel Density & Types

Different gravel sizes and shapes have unique densities that affect weight calculations.

Crushed Stone (#57)

Angular 3/4" stones, ideal for driveways and base material

Density: 100 lb/ft³ (1600 kg/m³)

Pea Gravel

Smooth 3/8" rounded stones, perfect for walkways and patios

Density: 96 lb/ft³ (1540 kg/m³)

River Rock

Decorative smooth stones 1-3", great for landscaping beds

Density: 100 lb/ft³ (1600 kg/m³)

Crushed Gravel (#411)

Fine crusite mix, excellent for compacting and base layers

Density: 105 lb/ft³ (1680 kg/m³)

Decomposed Granite

Natural tan/gold color, popular for pathways in the Southwest

Density: 100 lb/ft³ (1600 kg/m³)

Impact: A cubic foot of crushed stone weighs more than the same volume of pea gravel due to better packing.

Cost Factors for Gravel

Variables affecting cost:

  • Gravel type: Premium vs. standard materials
  • Delivery distance: Transportation costs for bulk orders
  • Local supply: Regional availability and demand
  • Quantity: Bulk discounts for larger orders
  • Season: Weather affects supply and demand

Money-saving tip: Compare prices per cubic yard vs. per ton, and consider delivery minimums.

Engineering Reference

For roadway material practice and aggregate guidance, review federal geotechnical engineering resources.

The First Delivery: Not Enough

My driveway project started with a guess. The driveway was roughly 20 feet long and 10 feet wide. I wanted 4 inches of gravel. I eyeballed it, ordered 2 cubic yards, and felt pretty good about myself.

The truck dumped the pile. I spread it out. Covered about two-thirds of the driveway. The last third was bare dirt staring back at me.

Second delivery fee: $75. The gravel itself was only $45 per cubic yard. I paid more for the truck to come back than for the material I needed.

The Math I Should Have Done First

The formula is three multiplications and one division. That's it.

My driveway: 20 ft × 10 ft × 4 inches deep. But you can't mix feet and inches — convert the depth to feet first: 4 inches ÷ 12 = 0.333 feet.

Volume=L×W×D=20×10×0.333=66.6 cubic feet\text{Volume} = L \times W \times D = 20 \times 10 \times 0.333 = 66.6 \text{ cubic feet}

Gravel is sold in cubic yards. One cubic yard = 27 cubic feet.

66.627=2.47 cubic yards\frac{66.6}{27} = 2.47 \text{ cubic yards}

I needed 2.47 cubic yards. I ordered 2. No wonder I came up short.

The Second Delivery: Too Much

Overcompensating from my first mistake, I ordered 2 full cubic yards for the remaining third. That's roughly double what I needed for the gap. The extra gravel sat in a pile next to my garage for six months. My neighbor started calling it "the monument."

The right order would have been 1 cubic yard — maybe 1.25 with a compaction buffer. But I was frustrated and rounded up aggressively. Lesson learned: math is cheaper than pride.

The Compaction Factor Nobody Mentions

Loose gravel settles. Rain, traffic, and gravity compress it over time. Most gravel suppliers recommend ordering 10-15% extra to account for compaction. Some materials compact more than others — crushed stone settles more than river rock because the angular pieces lock together tighter.

For my 2.47 cubic yards, adding 10% compaction buffer: 2.47×1.10=2.722.47 \times 1.10 = 2.72 cubic yards. Round up to 3. That's what I should have ordered from the start.

Always round up to the nearest half or whole cubic yard. Suppliers don't deliver in decimals, and a small surplus beats a second delivery fee every time.

How Thick Should Your Gravel Be?

This depends on what's going under it and what's driving on it:

ApplicationRecommended DepthNotes
Walkway / path2-3 inchesFoot traffic only
Patio base4 inchesUnder pavers or flagstone
Driveway4-6 inchesVehicle traffic, may need base layer
Heavy vehicle area8-12 inchesTrucks, RVs, equipment

For driveways, many contractors recommend a two-layer approach: 3-4 inches of larger crushed stone (#2 or #3) as a base, topped with 2-3 inches of finer gravel (#57 or pea gravel) for a smooth surface. The base layer handles drainage and load-bearing; the top layer handles aesthetics and tire comfort.

The Third Time: Getting It Right

For a small side path — 15 ft × 3 ft × 2 inches deep — I finally did the math first.

15×3×0.167=7.515 \times 3 \times 0.167 = 7.5 cubic feet. Divide by 27: 0.280.28 cubic yards. Add 10% compaction: 0.310.31 cubic yards. I ordered half a cubic yard.

Perfect coverage, tiny surplus, zero second trips. The gravel calculator does this in about 5 seconds. I spent $150 in extra delivery fees learning what a calculator could have told me for free.

It's the same lesson as shopping math — the numbers aren't hard, but eyeballing them costs real money.

Frequently Asked Questions

How much gravel do I need for a driveway?

Measure length × width × depth (in feet), divide by 27 to get cubic yards, then add 10-15% for compaction. A typical single-car driveway (20 ft × 10 ft × 4 inches) needs about 2.5-3 cubic yards. A two-car driveway (20 ft × 20 ft × 4 inches) needs 5-6 cubic yards.

How do you calculate cubic yards?

Multiply length × width × depth in feet to get cubic feet, then divide by 27 (since 1 cubic yard = 27 cubic feet). Make sure all measurements are in the same unit — convert inches to feet by dividing by 12 before multiplying.

How thick should gravel be for a driveway?

4-6 inches total for standard passenger vehicles. Ideally, use a two-layer system: 3-4 inches of larger crushed stone as a base for drainage and stability, topped with 2-3 inches of finer gravel for a smooth driving surface. Heavy vehicles (trucks, RVs) may need 8-12 inches total.

Don't Guess — Calculate

Measure your area, pick your depth, and get the exact cubic yards. Beats paying for a second delivery.

*Remember to add 10-15% for compaction. Your future self will thank you.

Frequently Asked Questions

How much gravel do I need for a driveway?
For a typical single-car driveway (10 × 20 ft) with 4 in of gravel depth, roughly 2.5 yd³ / 3.5 tons. For a two-car driveway (20 × 20 ft), double that.
How deep should the gravel layer be?
Driveways: 4-6 in with a compacted sub-base. Walkways and patios: 2-3 in over 2 in of crushed gravel base. Drainage / French drains: 6-12 in.
What type of gravel should I use?
Driveways: 3/4-inch crushed stone or crusher run. Walkways / patios: pea gravel or decomposed granite. Drainage: 3/4-inch clean crushed stone. Decorative: river rock or marble chips.
How much does gravel weigh?
Crushed stone and pea gravel weigh about 1.4-1.5 tons per cubic yard. River rock is slightly lighter at 1.3-1.4 tons/yd³.
Should I add extra for compaction?
Yes — add 5-10% for compaction, spillage, and uneven terrain. For driveways, pros often add 10-15% to ensure adequate coverage.
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