Gravel Calculator — Free Gravel Volume & Material Estimator
Calculate the exact gravel volume (cubic yards & cubic feet), total weight in tons, 50-lb bag count, and material cost for driveways, paths, patios, and foundations.
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Gravel Calculator: How to Calculate How Much Gravel You Need
Whether you are constructing a crushed stone driveway, paving a tranquil garden walkway with smooth pea gravel, setting up a patio fire pit, or preparing a foundation for a shed, ordering the correct quantity of gravel is vital. Ordering too little incurs expensive second-run dump truck delivery fees, while ordering too much leaves an unwanted mountain of stone on your lawn.
According to geological aggregate standards on Wikipedia's Gravel Overview, unconsolidated rock fragments vary significantly in weight depending on particle size and compaction friction. This free calculator handles all conversions instantly.
The Exact Mathematical Formulas
Cubic Feet = Area (sq ft) × (Depth in inches ÷ 12)
// 2. Volume in Cubic Yards
Cubic Yards = Cubic Feet ÷ 27
// 3. Factor Compaction & Waste (10% standard)
Cubic Yards (with waste) = Cubic Yards × (1 + Waste% ÷ 100)
// 4. Weight in Short Tons
Tons = Cubic Yards × Material Density (tons/yd³)
// 5. Number of 50-lb Bags
Bags (50 lb) = Math.ceil((Tons × 2000) ÷ 50)
Gravel Types & Densities
| Gravel Type | Density (tons/yd³) | Primary Application | Characteristics |
|---|---|---|---|
| Pea Gravel | 1.2 | Walkways, patios, dog runs | Smooth 3/8" rounded pebbles; comfortable for foot traffic. |
| Standard Gravel (#57) | 1.4 (Default) | Car driveways, drainage swales | Angular 3/4" crushed stones that lock together tightly. |
| Crushed Stone (Road Base) | 1.5 | Heavy road sub-bases, RV parking | Crushed rock mixed with stone dust; compacts hard. |
| Fine Gravel Screenings | 1.3 | Paver leveling beds, trail surfaces | Small 1/4" particles for smoothing voids. |
| River Rock | 1.4 | Dry creek beds, borders, landscaping | Naturally rounded 1"–3" stones for drainage. |
Recommended Gravel Depth Guide
How to Measure Your Area Accurately
Gravel Reference Chart (Standard 1.4 t/yd³ with 10% waste)
| Area (sq ft) | 2" Depth (Walkway) | 3" Depth (Patio) | 4" Depth (Driveway) | 6" Depth (Base) |
|---|---|---|---|---|
| 50 sq ft | 0.34 yd³ (0.47 t / 19 bags) | 0.51 yd³ (0.71 t / 29 bags) | 0.68 yd³ (0.95 t / 38 bags) | 1.02 yd³ (1.43 t / 57 bags) |
| 100 sq ft | 0.68 yd³ (0.95 t / 38 bags) | 1.02 yd³ (1.43 t / 57 bags) | 1.36 yd³ (1.90 t / 76 bags) | 2.04 yd³ (2.85 t / 114 bags) |
| 200 sq ft | 1.36 yd³ (1.90 t / 76 bags) | 2.04 yd³ (2.85 t / 114 bags) | 2.72 yd³ (3.80 t / 152 bags) | 4.07 yd³ (5.70 t / 228 bags) |
| 500 sq ft | 3.40 yd³ (4.75 t / 190 bags) | 5.09 yd³ (7.13 t / 285 bags) | 6.79 yd³ (9.51 t / 380 bags) | 10.19 yd³ (14.26 t / 570 bags) |
| 1,000 sq ft | 6.79 yd³ (9.51 t / 380 bags) | 10.19 yd³ (14.26 t / 570 bags) | 13.58 yd³ (19.01 t / 760 bags) | 20.37 yd³ (28.52 t / 1140 bags) |
How to Convert Cubic Yards to Tons
Gravel is usually sold by the ton, so after you know your volume in cubic yards you still need a weight conversion. The weight of one cubic yard changes with the material and its moisture: crushed stone averages 1.4–1.6 tons, pea gravel around 0.95–1.1 tons, river rock 1.2–1.35 tons, and decomposed granite about 1.4–1.5 tons. Multiply your cubic yards by the density of your material, and keep the waste allowance from the estimator so the supplier quote covers compaction and spillage.
In practice, most homeowners run the volume through this conversion once so they can order the correct tonnage in a single delivery. If your supplier quotes in half tons instead of full yards, divide that half ton by the density to get the equivalent volume, then re-run the calculator with the smaller footprint to keep your waste percentage accurate across both units.
| Material | Weight per cubic yard | Example: 2 yd³ weighs |
|---|---|---|
| Crushed stone (#57) | 1.4–1.6 tons | 2.8–3.2 tons |
| Pea gravel | 0.95–1.1 tons | 1.9–2.2 tons |
| River rock | 1.2–1.35 tons | 2.4–2.7 tons |
| Decomposed granite | 1.4–1.5 tons | 2.8–3.0 tons |
Verify your conversion with a simple sanity check: one cubic yard of most gravels covers about 100 square feet at 3 inches deep, or 50 square feet at 6 inches. If your tonnage looks far from that rule of thumb, recheck the depth you entered in inches and your waste percentage before you order.
Smart Ordering Tips
- Compare bulk vs. bags first: once a project passes roughly one cubic yard, a delivered truckload usually beats bag prices by 30–50%, which matters most on driveways and large paths.
- Order 5–10% extra, not more: bulk gravel cannot be returned once it is dumped, and surplus piles compact and collect weeds over time.
- Prepare a delivery pad: most drivers dump on tarps or plywood, so clear a level spot near the work area to avoid hauling gravel by wheelbarrow.
- Count on compaction: fresh gravel settles about 10% after the first heavy rain, so spread any leftover material after installation rather than before.
- Watch the slope: angular crushed stone locks together on inclines, while round pea gravel rolls downhill and needs an edge restraint.
Estimators like this one remove the guesswork, but they only help when the measurements are honest. Measure length and width at the widest points, decide the depth before you shop, and write the number down — the conversion table above turns those cubic yards into the exact tonnage your truck needs.