Gravel Calculator: Square Feet & Coverage

This gravel calculator works out the volume of gravel you need when you know the area in square feet and the desired depth. You enter the length, width, and depth, and it returns the volume in cubic feet and cubic yards, plus an estimated weight in tons. The first result shown is the total cubic feet of gravel required.

Formula

The basic formula for gravel volume is:

Volume (cubic feet) = Length (ft) × Width (ft) × Depth (ft)

Since depth is usually measured in inches, convert it to feet first by dividing by 12. Then, to get cubic yards, divide the cubic feet by 27 (because 1 cubic yard = 27 cubic feet). For weight, multiply cubic feet by the density of gravel, which typically ranges from 1.3 to 1.7 tons per cubic yard. The calculator uses 1.4 tons per cubic yard (about 105 lb per cubic foot) as a common average for dry, loose gravel.

Worked Example

Using the default values from the calculator above (length = 20 ft, width = 10 ft, depth = 3 in):

1. Convert depth to feet: 3 in ÷ 12 = 0.25 ft
2. Calculate area: 20 ft × 10 ft = 200 sq ft
3. Calculate volume: 200 sq ft × 0.25 ft = 50 cu ft
4. Convert to cubic yards: 50 cu ft ÷ 27 = 1.85 cu yd
5. Estimate weight: 50 cu ft × 1.4 tons/cu yd ÷ 27 = 2.59 tons

So for a 200 sq ft area at 3 inches deep, you need about 50 cubic feet or 1.85 cubic yards of gravel, weighing roughly 2.6 tons.

How to Use the Result

The result tells you how much gravel to order, but it’s not the final number you should buy. Gravel settles and compacts, and you may lose some during spreading. Add 5–10% extra to your order to account for compaction and spillage. For example, if the calculator says 1.85 cubic yards, order about 2 cubic yards for a small project, or 2.1 cubic yards for a larger one.

The weight estimate matters for transportation. A standard pickup truck bed holds about 1.5–2 cubic yards of gravel, but check your truck’s payload rating. For larger amounts, delivery by dump truck is usually more practical and often cheaper per ton than bagged gravel from a home improvement store.

Common Mistakes and Misconceptions

One of the most frequent errors is mixing units. If you measure the length in feet but the depth in inches without converting, your volume will be off by a factor of 12. Always convert everything to feet before multiplying.

Another common mistake is assuming that square feet alone tells you how much gravel you need. Square feet only gives the area; you must multiply by the depth to get volume. Two areas of the same square footage can need very different amounts of gravel if one is 2 inches deep and the other is 6 inches deep.

People also confuse cubic yards with tons. Gravel is sold by the cubic yard (volume) or by the ton (weight). The relationship depends on the gravel’s density, which varies with the type of stone and moisture content. The calculator’s weight estimate is an average; for exact weights, ask your supplier for the specific density of the gravel you plan to buy.

Choosing the Right Depth

The depth you need depends on what the gravel is for:

• Walkways: 2–3 inches of compacted gravel is usually enough for a stable path.
• Driveways: 4–6 inches of gravel, often in two layers (a coarse base layer and a finer top layer), is typical for residential driveways.
• Drainage or base for pavers: 4–8 inches, depending on soil conditions and expected load.
• Mulch or decorative ground cover: 2–3 inches is common for appearance and weed suppression.

If you’re unsure, a deeper layer is safer than a shallow one, but it costs more. For driveways, consider the weight of vehicles; a heavier vehicle like a truck needs a thicker base than a compact car.

Gravel Types and Density

Gravel is not a single material. It ranges from fine crushed stone (like limestone screenings) to large river rock. The density affects the weight estimate:

• Crushed stone (#57 or #67): about 1.4 tons per cubic yard
• Pea gravel: about 1.4–1.6 tons per cubic yard
• River rock (smooth, rounded): about 1.5–1.7 tons per cubic yard
• Bank gravel (with sand and clay): about 1.6–1.8 tons per cubic yard

If you need a precise weight for transport, ask your supplier for the specific gravity or weight per cubic yard of the exact material. The calculator’s 1.4 tons per cubic yard is a reasonable middle ground for most projects.

Estimating Cost

While this calculator doesn’t include prices (they vary by region and supplier), you can estimate cost by multiplying the cubic yards by the price per cubic yard. As of recent years, bulk gravel typically costs between $15 and $75 per cubic yard, depending on the type and delivery distance. Bagged gravel from a store is far more expensive per cubic yard—often $100 or more—but is convenient for small patches. For any project over a few square feet, bulk delivery is almost always cheaper.

To get a quote, call local landscaping or construction supply companies and ask for a price per cubic yard, including delivery. Be ready to tell them the cubic yards you need (from the calculator) and your zip code for delivery fees.

Safety and Handling

Gravel is heavy—a single cubic yard can weigh over a ton. When loading or moving gravel, use proper lifting techniques to avoid back injury. Wear gloves and eye protection when shoveling, as sharp edges on crushed stone can cut skin. For large deliveries, keep children and pets away from the drop zone. If you’re spreading gravel yourself, use a rake and a wheelbarrow for small areas; for larger areas, consider renting a small skid-steer or hiring a landscaper.

Dust from gravel can irritate lungs, especially if it contains silica. If you’re working in a dry, dusty area, wear a dust mask. Wet the gravel slightly before spreading to reduce dust, but be aware that wet gravel is heavier and more difficult to move.

Frequently Asked Questions

How many square feet does a ton of gravel cover?

At a 3-inch depth, a ton of gravel (about 0.7 cubic yards) covers roughly 75–80 square feet. At 2 inches deep, it covers about 110–120 square feet. The exact number depends on the gravel’s density and how well it compacts. Use the calculator to work backward: enter your area and depth, then note the tons result.

What is the difference between gravel and crushed stone?

Gravel is naturally rounded rock, often found in riverbeds or pits. Crushed stone is mechanically broken from larger rocks, giving it angular edges. Crushed stone locks together better for driveways and bases, while rounded gravel is more decorative and easier to walk on. Both are sold by the cubic yard or ton.

Should I add extra gravel to my order?

Yes, it’s wise to add 5–10% extra to account for compaction, spreading loss, and irregular ground. If the ground is uneven, you may need more than the calculator suggests because the depth will vary. For a first-time project, adding 10% is a safe margin.

How do I measure an irregularly shaped area?

Break the area into rectangles, triangles, or circles, calculate each separately, then add the volumes together. For a triangle, use (base × height) / 2 for the area. For a circle, use π × radius². The calculator handles each shape if you enter its dimensions separately and sum the results.

Can I use the calculator for sand or soil?

Yes, the volume calculation works for any bulk material. However, the weight estimate (1.4 tons per cubic yard) is specific to gravel. Sand is typically heavier (about 1.6 tons per cubic yard), and topsoil is lighter (about 1.1 tons per cubic yard). Adjust the density factor accordingly if you need weight.

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in length | Length | ft | 20 | 0
in width | Width | ft | 10 | 0
in depth | Depth | in | 3 | 0
out cubic_ft | Volume | cu ft | length * width * (depth / 12) | 2
out cubic_yd | Volume | cu yd | cubic_ft / 27 | 2
out tons | Estimated weight | tons | cubic_ft * 1.4 / 2000 | 2