Calculate Gravel for Driveways, Paths, and Drainage
Gravel projects fail when you order the wrong type or too little material. A driveway with insufficient depth develops ruts and potholes within months. This calculator determines how many tons or cubic yards of gravel you need based on area, depth, and gravel type—plus helps you choose the right stone for your application.
Understanding Gravel Types
Gravel isn't generic—each type serves specific purposes:
- Crushed stone (¾"): Driveways, base layers. Angular edges lock together for stability. Most common choice.
- Pea gravel (⅜"): Pathways, playgrounds, decorative areas. Smooth, rounds, comfortable to walk on barefoot but shifts under vehicle traffic.
- Crusher run (¼"-¾" mix): Best driveway base. Contains stone dust that compacts into a cement-like surface when wet and rolled.
- River rock (1-3"): Decorative landscaping, drainage. Smooth stones don't compact well for traffic areas.
- #57 stone (¾"): Drainage applications, French drains, septic systems. Large voids allow water flow.
Measuring for Gravel
1. Calculate area: Measure length × width in feet. For irregular shapes, break into rectangles or use the average width along the length.
2. Determine depth: Driveways need 4-6 inches of gravel (deeper for soft soil or heavy vehicles). Paths need 2-4 inches. Drainage layers need 6-12 inches.
3. Account for compaction: Gravel compacts 20-30% when driven on or rolled. Order 25% more than calculated volume to account for settling.
4. Convert to tons: Gravel is sold by the ton (sometimes cubic yard). Average gravel weighs 1.4-1.7 tons per cubic yard depending on type. Crushed stone is denser; pea gravel is lighter.
Installation Best Practices
Excavate to proper depth: Remove sod, roots, and soft soil. If you're adding 4 inches of gravel, excavate 6 inches to allow for compaction and base material.
Install landscape fabric: Place commercial-grade woven geotextile fabric over excavated soil before adding gravel. This prevents gravel from sinking into soft ground and weeds from growing up through the stone.
Build up in layers: For driveways, install a base layer of crusher run (3-4 inches), compact with a plate compactor or roller, then add a top layer of ¾" crushed stone (2-3 inches). Two compacted layers outlast a single thick layer.
Crown the driveway: Create a gentle peak down the center (2-3% slope) so water runs to the edges, not down the middle. Standing water erodes gravel and creates ruts.
Common Gravel Mistakes
Using the wrong stone size: Large stones (2-3") create a bumpy surface unsuitable for walking or vehicle traffic. Fine stone (#8, #9) compacts too much and becomes muddy. Stick to ¾" for most applications.
Skipping the base layer: Putting pretty pea gravel directly on dirt guarantees it will sink and disappear within a year. Always use crusher run or compacted stone dust as a base.
Not compacting: Loose gravel shifts, rutts, and spreads. Rent a plate compactor ($50-80/day) for driveways and paths. Compact in 2-inch lifts (layers) by watering lightly and running the compactor over each layer 3-4 times.
Ordering too little: Running out mid-project means additional delivery fees (often $50-150). Always round up to the next half-ton or full cubic yard.
Total Materials Needed
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Pro Tips
- Driveways: 4–6" depth with compacted base
- Walkways: 2–3" depth is usually sufficient
- French drains: Fill trench with 3/4" gravel
- Gravel weighs about 1.4 tons per cubic yard (varies by type)
- Pea gravel is lighter (~1.3 tons/yd³), crushed stone heavier (~1.5 tons/yd³)
- Order 10–15% extra — gravel always seems to disappear
Frequently Asked Questions
Q: How much does gravel cost?
A: $15-50 per ton delivered depending on type and distance. Crusher run is cheapest ($15-25/ton); decorative river rock is most expensive ($40-75/ton). Delivery adds $50-150 for small loads; free delivery is common for 10+ tons.
Q: How do I keep gravel in place?
A: Install edge restraints (steel or aluminum edging, pressure-treated timbers, or Belgium blocks). Without edges, gravel migrates into lawns and planting beds. Compact thoroughly—loose gravel shifts more than compacted.
Q: Can I drive on pea gravel?
A: Not for regular vehicle traffic. Pea gravel's round shape doesn't lock together, so it shifts and creates ruts. Use ¾" crushed stone for driveways. Pea gravel is fine for decorative areas and low-traffic paths.
Q: How often does gravel need replenishment?
A: Properly installed gravel driveways need fresh stone every 3-5 years. Add 1-2 inches when ruts develop or stone becomes sparse. Paths need refreshing every 2-3 years.
Q: What's the difference between cubic yards and tons?
A: Cubic yards measure volume; tons measure weight. Gravel suppliers sell by weight (tons) but you calculate volume (cubic yards). Use conversion: 1 cubic yard ≈ 1.4 tons for most gravel types.
How to Calculate Gravel
Calculating the right amount of gravel requires a simple four-step process:
- Measure the area in feet: Length × Width. For irregular shapes, break into rectangles and add the areas.
- Determine the depth: Typical depths are:
- 2–3 inches for paths and walkways
- 4–6 inches for driveways (4" minimum; 6" for soft or high-traffic areas)
- 6–12 inches for drainage layers and French drains
- 1–2 inches for decorative landscaping
- Apply the formula: (Length ft × Width ft × Depth in) ÷ 324 = cubic yards
Example: A 12 ft × 50 ft driveway at 4" deep: (12 × 50 × 4) ÷ 324 = 7.4 cubic yards - Convert to tons (optional): Cubic yards × 1.4 = approximate tons
7.4 cubic yards × 1.4 = 10.4 tons (varies by gravel type; crushed stone is heavier, pea gravel lighter) - Add 10% for waste and compaction: Gravel settles 20–30% when compacted. Order 10–15% extra to account for settling and spillage.
Gravel Coverage Chart
Use this table to estimate coverage for different depths. These are approximate values for standard crushed stone or pea gravel.
| Depth | Coverage per Cubic Yard | Coverage per Ton |
|---|---|---|
| 1 inch | ~324 sq ft | ~232 sq ft |
| 2 inches | ~160 sq ft | ~115 sq ft |
| 3 inches | ~108 sq ft | ~77 sq ft |
| 4 inches | ~81 sq ft | ~58 sq ft |
| 6 inches | ~54 sq ft | ~38 sq ft |
| 12 inches | ~27 sq ft | ~19 sq ft |
Types of Gravel & Best Uses
Different gravel types serve specific purposes. Choose based on your project and budget:
- Crushed stone (¾"): Angular edges lock together for stability. Best for driveways and base layers. Cost: $15–30/ton. Density: ~1.5 tons/cubic yard.
- Crusher run (¼"–¾" mix): Stone dust + gravel mix that compacts into a cement-like surface when wet and rolled. Ideal for driveway base layers. Cost: $15–25/ton. Best compaction performance.
- Pea gravel (⅜"): Smooth, rounded stones. Comfortable for walking barefoot. Not suitable for driveways (shifts under vehicle weight). Best for paths, playgrounds, and decorative areas. Cost: $20–40/ton. Density: ~1.3 tons/cubic yard.
- River rock (1–3"): Large, smooth, decorative stones. Doesn't compact; shifts easily. Use for landscaping, dry creek beds, and water features only. Cost: $40–75/ton. Poor for traffic areas.
- #57 stone (¾"): Uniform size, crushed angular stone. Excellent drainage characteristics. Use for French drains, septic systems, and underground utilities. Cost: $20–35/ton.
- Jersey shore gravel: Mixed shells, sand, and small stones. Compacts well, inexpensive. Regional availability. Cost: $10–20/ton.
- Marble chips: White, decorative, expensive. Use only for high-end landscaping. Cost: $75–150/ton.
Common Gravel Projects & Calculations
Here are typical project sizes to help you estimate your needs:
Driveway Gravel (12 ft × 50 ft, 4" deep)
- Cubic yards: 7.4 yd³
- Tons: ~10.4 tons (crushed stone)
- 50 lb bags: ~400 bags
- Estimated cost: $155–310 (bulk delivery)
- Note: Use crushed stone or crusher run in 2 layers: 3" base + 1" top finish
Patio Base (10 ft × 12 ft, 4" deep)
- Cubic yards: 1.48 yd³ (round to 1.5)
- Tons: ~2.1 tons
- 50 lb bags: ~110 bags
- Estimated cost: $35–65 (bulk) or $350–450 (bags)
- Note: Crusher run compacts best for patio pavers or travertine tiles
French Drain (50 ft length, 1 ft wide, 1 ft deep)
- Cubic yards: 1.85 yd³
- Tons: ~2.6 tons (#57 stone preferred)
- Estimated cost: $40–90
- Note: Use perforated drain pipe + landscape fabric + #57 stone gravel
Pathway (40 ft × 2 ft, 2" deep)
- Cubic yards: 0.49 yd³ (round to 0.5)
- Tons: ~0.7 tons
- 50 lb bags: ~35 bags
- Estimated cost: $12–25 (bulk) or $140–210 (bags)
- Note: Pea gravel or crusher run; 2–3" is comfortable for walking
Decorative Landscaping (20 ft × 15 ft, 3" deep)
- Cubic yards: 2.78 yd³
- Tons: ~3.9 tons (pea gravel or river rock)
- Estimated cost: $65–150
- Note: River rock is more expensive but lasts longer without weeding
Tips for Ordering Gravel
- Always order 10–15% extra: Gravel settles 20–30% when compacted. A shortage mid-project means additional delivery charges ($50–150 per trip).
- Check delivery minimums: Most suppliers have a 3–5 ton minimum. Smaller projects may cost more due to delivery fees ($50–150). Ask about bulk discounts for orders over 10 tons.
- Ask about compaction rate: Ask your supplier for the material's compaction percentage. Crusher run compacts 25–35%; crushed stone compacts 15–25%; pea gravel compacts 10–15%.
- Get a quote on delivery: Delivery costs vary by distance. Some suppliers include delivery for large orders (10+ tons). Compare bulk delivery vs. bagged pricing.
- Schedule delivery for crew work: Gravel should be spread and compacted within 1–2 days of delivery. Uncompacted piles settle unevenly and can shift. Plan to rent a plate compactor if you have a large area.
- Know your vehicle capacity: A standard pickup truck holds 1.5–2 tons; a dump truck holds 10–15 tons. Multiple small pickups cost more in time/fuel than one bulk delivery.
- Ask about colors and types: Standard crushed stone is gray; decorative colors (red, brown, white) cost more. Request samples before committing to large orders.