Gravel Calculator
To calculate how much gravel you need, multiply length × width × depth (in feet), divide by 27 to get cubic yards, then multiply by ~1.4 to estimate tons. For example, a 10 ft × 10 ft area at 3 inches deep needs about 1.2 cubic yards.
Enter length, width (feet) and depth (inches), get cubic yards and estimated tons, with every step shown.
How to calculate how much gravel you need
Enter the length and width of the area in feet and the desired gravel depth in inches, then press Calculate. The calculator converts the depth to feet, finds the volume in cubic feet, converts to cubic yards (the unit gravel is sold in), and estimates the weight in tons, with every conversion on screen.
Typical depths: 2–3 inches for garden paths, 4 inches for patios, and 4–6 inches for driveways that carry cars. When in doubt, go deeper, thin gravel migrates and ruts.
Gravel calculation formula (cubic yards to tons)
The method is volume first, weight second. Volume = length × width × depth, with all three in feet, so inches of depth are divided by 12 first. Divide cubic feet by 27 to get cubic yards. Then multiply by about 1.5 tons per cubic yard, the standard planning density for crushed gravel (real densities run 1.4–1.7 depending on stone type and moisture).
The tonnage is an estimate for ordering and delivery planning, quarries batch by weight, but your project is defined by volume. The calculator shows both so you can speak either language at the yard.
Worked example
Example: 20 ft × 10 ft driveway, 4 in deep
Step 1, Depth to feet: 4 in ÷ 12 = 0.333 ft.
Step 2, Cubic feet: 20 × 10 × 0.333 = 66.67 ft³.
Step 3, Cubic yards: 66.67 ÷ 27 = 2.47 yd³.
Step 4, Tons: 2.47 × 1.5 = 3.70 tons.
Ordering: round up to 2.5–3 cubic yards (about 4 tons) to cover compaction and spillage. A single-axle dump truck typically hauls 5–7 tons, so this order fits comfortably in one small load.
More examples: 12 × 12 ft patio at 3 in → 1.33 yd³ (≈2 tons); 30 × 10 ft path at 2 in → 1.85 yd³ (≈2.8 tons).
Common mistakes
- Entering depth in feet: the depth field expects inches, typing 4 for “4 feet” instead of “4 inches” over-orders by 12×. The label says inches; double-check.
- Ordering exactly the computed amount: gravel compacts 10–20% under traffic and some always spills. Order 5–10% extra.
- Using volume weight as exact: 1.5 tons/yd³ is a planning figure. Wet gravel is heavier; pea gravel is lighter. For structural work, ask the quarry for the actual density.
- Ignoring the subgrade: soft soil swallows the first inch or two of gravel. Compact the soil first or add depth.
When to use it
Use this calculator for driveways, parking pads, garden paths, French drains, shed bases, and dog runs, anywhere crushed stone, pea gravel, or crusher run goes down. For the raw volume without the weight estimate, the cubic yard calculator does the same volume math; for paved surfaces, see the asphalt calculator.
Full walkthrough: a garden path
Say the path is 30 ft long, 3 ft wide, and you want 3 inches of pea gravel. Enter 30, 3, and 3: depth 3 div 12 = 0.25 ft; volume 30 x 3 x 0.25 = 22.5 ft3; yards 22.5 div 27 = 0.83 yd3; tons 0.83 x 1.5 = 1.25 tons. Order 1 yard (about 1.5 tons) – landscape suppliers sell by the half yard, and the extra covers the edges where gravel scatters.
Frequently asked questions
Compute volume (length × width × depth in feet), divide by 27 for cubic yards, then multiply by 1.5 for tons. A 20×10 ft driveway at 4 inches needs about 2.5 cubic yards (≈4 tons). Enter your dimensions above for the exact figure.
Roughly 1.4 to 1.7 tons depending on stone type and moisture. This calculator uses 1.5 tons per cubic yard, the standard planning figure. Your quarry can give the exact density of their product.
Four to six inches after compaction for driveways carrying cars, 4 inches minimum over a firm, compacted subgrade. Garden paths need only 2–3 inches.
Yes. Order 5–10% more than calculated to cover compaction (gravel settles 10–20% under traffic), spillage during delivery, and uneven subgrade.
Crusher run (crush-and-run) or #57 stone over a compacted base, angular stones lock together under tires. Round pea gravel shifts and ruts under cars; save it for paths and landscaping.
About two-thirds of a cubic yard (one ton ÷ 1.5 tons/yd³ ≈ 0.67 yd³). At 4 inches deep, one ton covers roughly 45 square feet. The calculator above gives your exact figure.