How Much Gravel Do I Need? Gravel Calculator Guide (2026)
Quick Answer
- *The gravel formula: Volume (yd³) = Length (ft) × Width (ft) × Depth (in) ÷ 324
- *A standard 2-car driveway (12’ × 20’) at 3 inches deep needs about 2.2 cubic yards of top-coat gravel.
- *1 cubic yard of gravel weighs approximately 1.4–1.7 tons depending on type (ASTM D448).
- *Gravel costs $10–$50 per ton for materials; full driveway installation runs $1,500–$3,000 (HomeAdvisor, 2025).
The Gravel Formula
Figuring out how much gravel you need comes down to one straightforward calculation. Volume in cubic yards is what gravel is sold in, so that’s your target number.
Volume (cubic yards) = Length (ft) × Width (ft) × Depth (inches) ÷ 324
The number 324 is the conversion factor that bridges square feet and inches into cubic yards (there are 324 square feet of surface area in one cubic yard at one inch deep).
For metric users: Volume (m³) = Length (m) × Width (m) × Depth (m)
Once you have the volume in cubic yards, convert to tons if your supplier sells by weight:
Weight (tons) = Volume (yd³) × 1.4 (for standard crushed stone or pea gravel)
Example: Gravel Driveway (12 × 20 feet)
A typical 2-car driveway is 12 feet wide by 20 feet long. At a 3-inch top-coat depth:
12 × 20 × 3 ÷ 324 = 2.22 cubic yards
At 1.5 tons per cubic yard (crushed stone #57): 2.22 × 1.5 = 3.3 tons
Add 10–15% for waste and settling, so order about 2.5 cubic yards or 3.75 tons. Our gravel calculator handles this automatically.
Recommended Gravel Depths by Project
The right depth depends entirely on what the gravel will be doing. A decorative garden border needs far less than a driveway bearing vehicle weight. According to University Extension Services, the most common residential depth is 2–4 inches for driveways and 2–3 inches for pathways.
| Project Type | Recommended Depth |
|---|---|
| Driveway (top coat) | 2–3 inches |
| Driveway (base layer) | 4–6 inches |
| Pathway / walkway | 2–3 inches |
| Landscaping / borders | 2–3 inches |
| Drainage / French drain | 6–12 inches |
| Playground safety surface | 6–9 inches |
For driveways, the base layer matters as much as the top coat. A 4–6 inch compacted base of road base or crusher run prevents the top layer from sinking into soft soil. Skip the base and you’ll be regrading every season.
Gravel Types: Weight and Best Uses
Not all gravel is the same weight. Per ASTM D448 aggregate standards, gravel density ranges from about 1.3 to 1.6 tons per cubic yard. Using the wrong weight estimate can mean ordering significantly too little or too much.
| Gravel Type | Weight per yd³ | Best Use |
|---|---|---|
| Pea gravel (3/8”) | ~1.4 tons | Pathways, playgrounds, decorative |
| Crushed stone (#57) | ~1.5 tons | Driveways, drainage, base fill |
| Road base / CR6 | ~1.6 tons | Driveway base layer, compaction |
| River rock | ~1.35 tons | Landscaping, drainage beds |
| Decomposed granite | ~1.3 tons | Pathways, xeriscaping, patios |
Pea gravel (3/8 inch diameter) is the most popular residential choice. According to landscaping industry guides, 0.5 cubic yards covers approximately 100 square feet at 2 inches deep. It’s soft underfoot and attractive, but it shifts under vehicle tires — stick to crushed stone for driveways.
Gravel Cost Estimates (2025)
Gravel pricing varies by region, type, and whether you’re buying bulk delivery or bags. According to HomeAdvisor (2025), here’s what to expect:
| Cost Item | Low | High | Notes |
|---|---|---|---|
| Material (per ton) | $10 | $50 | Varies widely by type and region |
| Material (per cubic yard) | $15 | $75 | Pea gravel on high end; road base on low |
| Delivery charge | $50 | $150 | Per load, often free over a threshold |
| 2-car driveway (installed) | $1,500 | $3,000 | 12’ × 20’, includes labor |
| Bags (0.5 cu ft each) | $4 | $8 | Only practical for very small areas |
Buying in bulk is almost always cheaper than bags. A cubic yard of pea gravel from a landscape supplier costs $30–$75 delivered. That same cubic yard in 0.5-cubic-foot bags from a home center would cost $200–$400. Order bulk whenever you need more than 0.5 cubic yards.
How Much Gravel Does the US Use?
Gravel is not a niche material. According to the US Geological Survey (USGS), the United States produces approximately 900 million tons of crushed stone and 900 million tons of sand and gravelper year — making them the #1 and #2 most-mined non-fuel minerals in the country. Combined, that’s nearly 6 tons of aggregate per American per year.
Most of that goes to roads, concrete, and construction. But residential landscaping and driveways represent a meaningful slice — and understanding the math behind your order means you don’t overpay or run short mid-project.
Tips for Ordering Gravel
Always Add 10–15% Extra
Gravel compresses. It settles into low spots. Some spills during delivery. A 10–15% buffer is standard practice. If your calculation gives you 3 cubic yards, order 3.5.
Measure Irregular Shapes
Most yards aren’t perfect rectangles. For irregular shapes, break the area into rectangles, calculate each section separately, and add them together. For circular areas, use: Area = π × radius², then plug into the main formula.
Check Delivery Minimums
Most bulk suppliers have a 1–2 cubic yard minimum for delivery. If you need less, you may be better off picking up bags from a home improvement store, or using a pickup truck and a local landscape yard.
Consider a Landscape Fabric Underlayer
For pathways and decorative beds, a weed barrier fabric under the gravel dramatically reduces weeding work. It doesn’t affect your volume calculation — you still need the same depth of gravel on top.
Calculate exactly how much gravel you need
Use our free Gravel Calculator →Also useful: Mulch Calculator · Concrete Calculator · Paint Calculator
Frequently Asked Questions
How many cubic yards of gravel do I need?
Use the formula: Volume (cubic yards) = Length (ft) × Width (ft) × Depth (inches) ÷ 324. For example, a 12 × 20 foot driveway at 3 inches deep needs 12 × 20 × 3 ÷ 324 = 2.2 cubic yards. Always add 10–15% extra for compaction and waste.
How deep should gravel be for a driveway?
A finished driveway typically needs 2–3 inches of top-coat gravel over a 4–6 inch compacted base layer of road base or crusher run. For a new driveway from scratch, plan on 6–9 inches total depth. For an existing driveway you’re topping off, 2–3 inches is usually sufficient.
How much does a ton of gravel cover?
At 2 inches deep, one ton of gravel covers approximately 80–100 square feet. At 3 inches deep, one ton covers about 55–65 square feet. Coverage varies by gravel type — lighter materials like pea gravel spread slightly farther than dense road base.
How many square feet does a yard of gravel cover at 2 inches deep?
One cubic yard of gravel covers 162 square feet at 2 inches deep. The quick reference: at 1 inch deep it covers 324 sq ft, at 2 inches it covers 162 sq ft, at 3 inches it covers 108 sq ft, and at 4 inches it covers 81 sq ft.
What is the best gravel for a driveway?
For a driveway base layer, use road base (crusher run/CR6) — it compacts hard and drains well. For the top layer, crushed stone #57 is the most popular choice: it locks together under traffic, drains well, and looks clean. Pea gravel is attractive but tends to scatter under vehicle tires, making it better for pathways than driveways.
How much does gravel cost per ton?
According to HomeAdvisor (2025), gravel costs $10–$50 per ton for the material, or $15–$75 per cubic yard depending on type and location. Delivery adds $50–$150 per load. The average American homeowner spends $1,500–$3,000 to gravel a standard 2-car driveway (12’ × 20’) fully installed.