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Gravel calculator: volume, weight, and tons
Estimate the volume and weight of the gravel you need for a path, a driveway, a compacted base, or a drainage bed. The tool works in metric (Europe/LatAm) or American (US) units, shows the result in m³ or yd³, kg or lb, and tons, lets you adjust the density based on your supplier, and includes an optional cost calculation.
Last reviewed: July 2026 · How we calculate
Input data
Adjust the value based on your supplier.
Results
Enter the data and press Calculate.
Results are estimates. Always verify manufacturer or supplier specifications before buying.
How to calculate the gravel you need
Estimating gravel means calculating a volume and then converting it into a weight, because almost all suppliers sell and load the material by the ton. The process has four steps and this calculator handles them for you, but it helps to understand them so you can check that the result makes sense:
- Area volume. Multiply length × width × depth of the area you are covering. That product gives you the space the gravel must fill.
- Waste adjustment. A small percentage (5% by default) is added to the volume to cover real job-site losses: gravel lost while spreading, settling from compaction, and measurement errors.
- Conversion to weight. The adjusted volume is multiplied by the gravel's density (how many kilos each cubic meter holds) to get the total weight of the material.
- Conversion to tons. The weight is divided by 1000 in the metric system or by 2000 in the American system, since that is the unit you will be charged in and that transport is planned around.
An important detail of the American system: the depth is entered in inches and the calculator converts it to feet (÷ 12) before multiplying, so the volume ends up in cubic feet and is then converted to cubic yards.
Formula
For a rectangular area:
Adjusted volume = Volume × (1 + Waste ÷ 100)
Weight = Adjusted volume × Density
Tons = kg ÷ 1000 (metric) or lb ÷ 2000 (American, short tons)
In the American system the depth is converted from inches to feet (÷ 12) and the volume in cubic feet is also shown in cubic yards:
Practical example
Suppose an area of 5 m long × 3 m wide with a depth of 0.10 m, a density of 1600 kg/m³, and 5% waste (the calculator's default values):
| Area volume | 5 × 3 × 0,10 = 1,5 m³ |
|---|---|
| Volume with 5% waste | 1,5 × 1,05 = 1,575 m³ |
| Estimated weight | 1,575 × 1600 = 2520 kg |
| Weight in tons | 2520 ÷ 1000 = 2,52 tons |
This is exactly the result you will see if you press "Calculate" with the default values: 1.575 m³, 2520 kg, and 2.52 tons. If your supplier uses heavier or lighter gravel, change the density and the weight recalculates instantly.
Typical gravel density
Density is the value that most affects the final weight. Gravel usually runs around 1600 kg/m³ (about 100 lb/ft³), but it is not a fixed value: it changes with the type of stone, the aggregate size, and moisture. Loose gravel weighs less than compacted gravel, and wet gravel weighs more than dry gravel. If your supplier lists a specific density on the product sheet, enter it in the "Density" field to fine-tune the estimate.
Gradation: which gravel size to use for what
"Gravel" isn't a single material: the aggregate size (gradation) determines what it's for and how it behaves. Buying the wrong size is one of the most common mistakes in gardens and light construction:
| Pea gravel 3/8" (~10 mm) | Decorative finishes, paths, fine drains, and planters |
|---|---|
| Gravel 3/4" (~19 mm) | The standard for concrete and compacted bases |
| Gravel 1½" (~38 mm) | Sub-bases, coarse drainage, and fills |
| Decorative / river stone | Gardens and ground cover; doesn't compact well as a base |
For paths and driveways, the usual practice is to combine: a coarse layer below that drains and a fine layer on top that compacts and gives the finish. Density also varies with size and rock type (that's why the calculator lets you adjust it): the same bucket of fine gravel weighs more than one of round stone, because it leaves fewer voids.
Common mistakes when calculating gravel
- Using a generic density. Applying 1600 kg/m³ to any gravel can throw off the weight by several hundred kilos. Ask your supplier for the real figure whenever you can.
- Mixing up the depth unit. Don't mix centimeters with meters or inches with feet. In metric mode the depth is in meters; in American mode, in inches. The calculator handles the conversion for you.
- Not accounting for compaction. When you compact a base, the volume shrinks and you need more gravel than calculated in theory. Raise the waste if you are going to compact.
- Forgetting the waste. Buying the exact amount almost always leaves the job short. A margin of 5% to 10% avoids having to place a second order.
Frequently asked questions
What is the typical density of gravel?
Gravel usually runs around 1600 kg/m³ (about 100 lb/ft³), but the value changes with the type of stone, the aggregate size, and moisture. Loose gravel weighs less than compacted gravel, and wet gravel weighs more than dry gravel. Adjust the density field with your supplier's figure when you have it.
What depth of gravel should I use?
It depends on the use. For walkways and gardens, 5 to 8 cm is enough; for driveways, 10 to 15 cm is recommended, often over a coarser gravel base. For drainage, the depth is set by the design of the trench or bed.
Why calculate both the volume and the weight?
The volume (m³ or yd³) tells you how much space you will fill and helps plan the job, while the weight in tons is the unit most suppliers use to charge and load their trucks. Having both avoids surprises when ordering the material and comparing prices.
Does gravel need compaction?
For path and driveway bases, yes: the gravel is compacted with a plate compactor or roller so it doesn't sink under traffic. Compaction reduces the final volume, so it's a good idea to order a little extra. For drainage or decorative finishes, it is usually left loose.
Does the calculator use metric or short tons?
It depends on the system you choose. In metric mode the weight is divided by 1000, so the tons are metric (1000 kg). In American mode the weight in pounds is divided by 2000, so you get short tons, the unit common in the United States.
How do I estimate the cost of gravel?
You can fill in the price per volume (m³ or yd³) or the price per ton, depending on how your supplier charges. The calculator multiplies that price by the corresponding volume or tons and shows you the estimated cost. Both fields are optional and you can use only the one you need.
Compaction and layers: why to buy 10–15% extra
Gravel that arrives loose in the truck loses volume when compacted: count on 10–15% less once the roller or plate compactor has passed. If you calculated the exact volume of the hole to fill, you'll come up short — that's why this calculator's waste field also covers compaction.
Thickness depends on use: a pedestrian path needs just 5–8 cm (2–3 in) compacted; for vehicle traffic, 10–15 cm (4–6 in) in two separately compacted layers is recommended (coarse below, fine on top). One tip that saves years of maintenance: lay geotextile fabric between the soil and the gravel — it keeps stones from sinking into the ground and weeds from coming up, preserving the thickness you paid for.