Driveway Gravel Calculator: How Much Gravel to Order
Use a driveway gravel calculator by multiplying length by width by compacted depth; for a driveway about 20 ft by 10 ft at 4 in, the compacted amount is around 2.5 cubic yards. Underordering leaves bare spots, thin coverage, and extra delivery fees. We show layer-by-layer math, compacted-to-loose conversion, weight estimates, and cost estimates.
How much gravel do I need for my driveway?
Start with length by width by depth, then convert inches to feet before calculating volume. The result is usually ordered in cubic yards, then checked against tons using the gravel density for the chosen material. For driveways, add a compaction allowance and a waste allowance so the delivered pile matches the finished thickness.
Base formula
Use this structure: volume in cubic feet is found by multiplying length in feet × width in feet × depth in feet. Convert to cubic yards by dividing cubic feet by 27. If depth is given in inches, divide by 12 first. That is the shortest path from driveway size to supplier order quantity.
Worked example
A driveway that is about 20 ft long and 10 ft wide, with a compacted depth of around 4 in, uses roughly 67 cubic feet. Divide by 27 and you get about 2.5 cubic yards compacted. Add delivery looseness and a small waste allowance, and the order rises above that finished in-place number.
- Measure the driveway length and width.
- Choose the compacted depth for each layer.
- Convert inches to feet before multiplying.
- Calculate cubic feet, then divide by 27.
- Add compaction and waste allowances for ordering.
Most driveways should have a depth of 6"-8" of gravel.
What depth should a gravel driveway be?
Most driveways should have a depth of 6"-8" of gravel, while the entire driveway should be between 12" to 18" deep. The right depth depends on vehicle weight, traffic class, and subgrade condition. A minimum of 2-4 inches of gravel is a workable baseline, but heavier loads need more structure.
Match depth to use
Light-duty driveways can work with thinner sections when the subgrade drains well and the soil is firm. Heavier vehicles, soft clay, frequent turning, or uphill drives call for thicker layers. The practical rule is to size the subbase for support, the base for lock-up, and the surface for finish.
Layer targets
A layered driveway usually has a subbase, a base course, and a surface course. The subbase carries load and corrects weak soil. The base course firms the structure. The surface course gives the top riding layer. Each layer can use a different stone type and a different compacted thickness.
How do I calculate gravel for an irregular driveway?
Split the driveway into rectangles, triangles, L-shapes, or separate runs, then calculate each section on its own. Curves are easier when broken into short straight segments. Add the section volumes together, then apply the same compacted-to-loose and waste allowances used for a simple rectangle.
Step-by-step layout method
Mark the driveway on a sketch. Break a curved drive into measured chords. Break an L-shape into two rectangles that meet at right angles. For a sloped or widened area, measure each section separately and use the correct width and depth for that section only.
Section example
If one run is 30 ft by 10 ft and a second run is 15 ft by 8 ft, calculate each area separately, then apply the same depth. This avoids forcing a single width onto a shape that changes. The final order is the sum of all section volumes, adjusted for compaction and delivery waste.
Driveway gravel calculator table: layer by layer
The proof asset below uses a 20 ft by 10 ft driveway with three common layers. We show compacted depth, loose-order depth, cubic yards, tons, and a 10% waste allowance for each layer. The ton conversion uses the calculator’s 1.35 tons-per-cubic-yard factor.
| Layer | Compacted depth | Loose-order depth | Cubic yards | Tons | 10% waste allowance |
|---|---|---|---|---|---|
| Subbase | 4 in | 4.4 in | 2.47 | 3.33 | 2.72 yd³, 3.66 tons |
| Base course | 3 in | 3.3 in | 1.85 | 2.50 | 2.04 yd³, 2.75 tons |
| Surface course | 1 in | 1.1 in | 0.62 | 0.83 | 0.68 yd³, 0.91 tons |
| Total | 8 in | 8.8 in | 4.94 | 6.66 | 5.44 yd³, 7.32 tons |
This table shows the key ordering issue: compacted thickness is not the same as delivered loose volume. A supplier delivers a looser pile that settles after spreading and rolling. That is why compaction and waste are added after the finished-depth math, not before it.
How many tons of gravel do I need?
Convert cubic yards to tons with density, because tonnage changes by gravel type and moisture. The calculator uses a 1.35 tons-per-cubic-yard factor. Another calculator assumes average gravel density of 1600 kg/m³, and another assumes gravel equals 1.25 tonnes per cubic meter. That range is why the material choice matters.
Why density changes
Moisture, stone size, and void space all affect weight per volume. Crusher run, dense graded material, and rounded stone do not weigh the same per yard. If a supplier prices by the ton, the density assumption needs to fit the exact product, not just “gravel” in general.
Quick ton example
If a driveway needs 4.94 cubic yards compacted, the order weighs about 6.66 tons using 1.35 tons per cubic yard. Add 10% waste and the total becomes 7.32 tons. That is a more practical order target than stopping at the finished in-place volume alone.
What gravel type is best for a driveway base?
Use crusher run or road base for the subbase, use dense graded aggregate or #57 stone for the base layer, and reserve pea gravel for spots where a looser surface is acceptable. #57 crushed stone is used for driveways and drainage. Dense graded (DGA/QP) is listed for road base and high-compaction areas.
Layer selection rule
The lower the layer, the more the stone should lock together. The upper layer can be cleaner and easier to finish. Crusher run and road base work well below because they compact tightly. #57 stone and dense graded aggregate can fit the middle layer where support and drainage both matter.
Material use by layer
- Subbase: crusher run or road base
- Base course: dense graded aggregate or #57 crushed stone
- Surface course: #57 stone or pea gravel where a looser finish is acceptable
How do I estimate driveway gravel cost?
Multiply quantity by price per cubic yard or ton, then add delivery, edging, geotextile, grading, and compaction if needed. Price per ton is often better for dense materials, while price per yard is easier when the supplier sells by volume. The best comparison matches the supplier’s pricing unit.
Cost formula
Cost = material quantity × unit price. If the yard is priced at $X per cubic yard, use the loose-order cubic yards. If it is priced by ton, use the ton estimate from the density factor. Then add the separate line items that many quotes leave out.
Common add-on costs
- Delivery
- Edging
- Geotextile
- Grading
- Compaction labor
These extras matter because a low material quote can miss the real installed cost. A site with soft soil, drainage problems, or a long haul from the road often needs more prep than a simple flat pad.
How much extra gravel should I order for compaction?
Adjustments for compaction can be 5-30% extra, and waste and overrun can be 5-15% extra. For most driveway estimates, the clean workflow is to calculate finished compacted volume first, then add a compaction allowance, then add a waste allowance if delivery conditions call for it.
Practical ordering sequence
Finished depth comes first. Loose delivery depth comes second. Waste allowance comes last. That order prevents mixing up in-place thickness with the pile that arrives on the truck. The higher the compaction target, the more important this separation becomes.
How many cubic yards of gravel do I need for a driveway?
Cubic yards are the main ordering unit for gravel because they match supplier pricing and truck delivery sizes. Calculate cubic feet from length by width by depth, then divide by 27. For most driveway jobs, the answer should be shown in cubic yards first, with tons as the cross-check.
Frequently asked questions
How much gravel do I need for my driveway calculator
Multiply driveway length by width by compacted depth, then divide by 27 to get cubic yards. Add extra for compaction and waste before ordering. For a 20 ft by 10 ft driveway at 4 in, the compacted need is about 2.47 cubic yards before allowances.
How to calculate how much gravel I need for my driveway
Measure the driveway, convert inches to feet, and use length by width by depth. Turn cubic feet into cubic yards by dividing by 27. If the driveway has multiple layers, calculate each layer separately and add the results together for the total order.
How to figure how much gravel I need for my driveway
Break the driveway into simple sections, then calculate each section as its own rectangle or triangle. Use the finished compacted depth for each layer, not the loose pile height. Add 5-30% for compaction and 5-15% for waste if the delivery and site conditions call for it.
How many tons of gravel do I need for my driveway
Convert cubic yards to tons with the gravel density factor for the chosen material. The calculator uses 1.35 tons per cubic yard as the default. Because density changes with stone type and moisture, the same driveway volume can produce different ton totals.
What depth should a gravel driveway be
Most driveways should have a depth of 6"-8" of gravel, and the entire driveway should be between 12" to 18" deep. Light-duty use can start with a minimum of 2-4 inches, but heavier vehicles and weaker subgrade usually need thicker layers and better compaction.
How do I calculate gravel for an irregular driveway
Split the shape into rectangles, triangles, or separate runs, then calculate each piece on its own. Curved driveways are easiest when measured as short straight segments. Add the section volumes together, then convert the total into cubic yards and tons for ordering.