Gravel Calculator: How Much Gravel Do You Need for Your Project?
Learn how to use a gravel calculator: convert area and depth into cubic yards and tons, choose gravel depth and type, and avoid common ordering mistakes.
Order too little gravel and you pay for a second delivery. Order too much and you are left with a pile you did not need. A gravel calculator solves this by turning your project’s length, width and depth into the two numbers suppliers actually use: cubic yards and tons. This guide explains the formula behind the calculator, the right depth for common projects, how gravel weight affects your order, how gravel fits into landscaping and drainage plans, and the mistakes that cause most ordering errors.
In this guide, a ton means a US short ton (2,000 lb), not a metric tonne. The calculator labels imperial output in short tons and metric output in tonnes. Example weights use an assumed density; the tool uses the density of the selected material, so weight estimates can differ.
Key takeaways#
- Gravel is sold by volume (cubic yards) or weight (tons). Volume = length x width x depth, with everything in feet, divided by 27.
- As a rule of thumb, one cubic yard of gravel weighs roughly 1.35 to 1.5 tons, depending on the type and moisture.
- Common depths: about 2 to 3 inches for walkways and decorative beds, and 4 to 6 inches for driveways.
- Add roughly 10% for compaction and settling, and more on small orders.
- Convert inches to feet before multiplying. Mixing units is the most common calculator mistake.
What a Gravel Calculator Does#
A gravel calculator is a quick estimator. You enter the length and width of the area, choose a depth, and it returns the volume of material in cubic yards and the approximate weight in tons. The result depends entirely on what you enter, so inaccurate measurements lead to inaccurate orders. It is also an estimate: the actual weight of gravel changes with moisture and stone size, and the real amount you need changes with how well the ground is prepared and compacted.
Use it for planning and budgeting, then confirm quantities and weights with your supplier before you order. You can try it now with the Interior Tailor Gravel Calculator.
How to Use the Interior Tailor Gravel Calculator#
- Choose Metric or Imperial. Metric uses metres for length and width and centimetres for depth; Imperial uses feet and inches.
- Enter the length, width and gravel depth of a rectangular area. For a circle or irregular shape, calculate the area by hand first, or split the project into rectangles and calculate them separately.
- Choose the material: pea gravel, crushed stone, decomposed granite, river rock or coarse sand. Each uses a different built-in density estimate.
- Review the waste allowance, which starts at 10%, and select Calculate. Read the net volume, total to order and estimated weight in the selected measurement system.
The calculator has no direct bag-size or custom-density input. Use the bag conversion in our figuring gravel guide for packaged material, and ask your supplier to confirm the density and quantity for a bulk order.
The Gravel Formula, Step by Step#
Even if you plan to use a calculator, understanding the math helps you catch mistakes.
Step 1: Measure the area
For a rectangle, measure the length and width in feet. For a circle, measure the diameter, find the radius (half the diameter), and use area = 3.14 x radius x radius. For irregular shapes, split the area into rectangles, circles and triangles, calculate each one, and add them together.
Step 2: Convert depth to feet
| Depth (inches) | Depth (feet) |
|---|---|
| 1 in | 0.083 ft |
| 2 in | 0.167 ft |
| 3 in | 0.25 ft |
| 4 in | 0.333 ft |
| 6 in | 0.5 ft |
Step 3: Calculate cubic feet and cubic yards
- Cubic feet = length (ft) x width (ft) x depth (ft)
- Cubic yards = cubic feet / 27
Step 4: Convert cubic yards to tons
Multiply cubic yards by the weight per cubic yard of your gravel. Many suppliers use about 1.4 tons per cubic yard as a general figure for common gravel, though specific materials range from roughly 1.35 to 1.5 tons or more.
- Tons = cubic yards x tons per cubic yard (about 1.4 for typical gravel)
Step 5: Add an allowance
Gravel settles and compacts after it is spread, and some is lost in handling. A common planning allowance is about 10%, with suppliers suggesting more on smaller orders. Round up to the nearest delivery quantity your supplier offers.
How Deep Should Gravel Be?#
Depth drives your quantity more than any other input, so choose it for the job, not for convenience.
| Project | Typical depth | Notes |
|---|---|---|
| Decorative beds and garden paths | 2 to 3 inches | Enough to cover soil and suppress weeds when combined with edging |
| Walkways and patios | 2 to 3 inches | Smaller stone such as pea gravel is common for foot traffic |
| Driveways | 4 to 6 inches | Heavier loads and wet climates call for the upper end |
| Base layers and structural fill | About 6 inches | Often a coarser, compactable stone under a finishing layer |
Local conditions, soil type, traffic and drainage all affect the right depth. If the surface will carry vehicles or manage water, check with your supplier or a local contractor.
Depths above are planning examples, not a complete driveway construction specification. The surface, compacted base and excavation can require different depths. Design for the ground conditions and loads at your site.
Gravel Weight: Tons per Cubic Yard by Type#
The same volume of different stone can weigh noticeably different amounts, so tons and cubic yards are not interchangeable. Published figures vary by supplier, but these are commonly quoted approximations:
| Material | Approx. tons per cubic yard | Common use |
|---|---|---|
| Pea gravel | About 1.4 | Paths, patios, decorative areas |
| Crushed stone (#57) | About 1.5 | Driveways, drainage trenches |
| Road base / crusher run | About 1.5 to 1.7 | Base layers that compact firmly |
| Decorative river rock | About 1.35 | Garden beds and borders |
Always confirm the density with your supplier, since moisture and stone size change the figure.
Worked Examples#
These examples use 1.4 tons per cubic yard and a 10% allowance. Swap in your own numbers.
| Project | Calculation | Cubic yards | Tons | With 10% extra |
|---|---|---|---|---|
| Walkway, 20 ft x 3 ft x 2 in | 60 sq ft x 0.167 ft = 10 cu ft / 27 | 0.37 | 0.52 | 0.41 yd, 0.57 tons |
| Garden area, 12 ft x 12 ft x 3 in | 144 sq ft x 0.25 ft = 36 cu ft / 27 | 1.33 | 1.87 | 1.47 yd, 2.05 tons |
| Single driveway, 10 ft x 20 ft x 4 in | 200 sq ft x 0.333 ft = 66.7 cu ft / 27 | 2.47 | 3.46 | 2.72 yd, 3.80 tons |
| Double driveway, 20 ft x 20 ft x 4 in | 400 sq ft x 0.333 ft = 133.3 cu ft / 27 | 4.94 | 6.91 | 5.43 yd, 7.60 tons |
Figures are rounded. In practice you would round up to the next available order quantity.
Choosing the Right Gravel Type and Size#
- Pea gravel: small, rounded stones that suit walkways, patios and garden paths. It can shift underfoot, so use edging.
- Crushed stone: angular pieces that lock together and compact well, which is why it is a common driveway and drainage choice.
- Crusher run or road base: a mix of stone sizes with fine material that binds, often used as a compacted base layer.
- River rock and decorative stone: attractive for beds and borders, but rounded stones in larger sizes are generally not ideal for driveways.
- Color: design writers note that darker gravel often suits contemporary gardens, while warm-toned pea gravel pairs well with cottage and Mediterranean styles.
Design and Drainage Considerations#
Consider how the gravel surface connects to paths, planting and drainage. These design choices affect both your material order and site preparation:
- Permeable driveways: surface stone is only one part of the system. Confirm the base, soil and drainage design before estimating each layer.
- Paths and planting: calculate gravel paths separately from adjacent beds, and allow for edging and changes in width.
- Replacing a hard surface: removing concrete does not by itself establish a suitable gravel base. Check the ground preparation and drainage needs first.
- Stone and gravel combinations: deduct the area occupied by solid pavers when estimating gravel infill, while calculating the underlying base over its own full area.
- Drainage features: gravel can form part of a drainage trench or rain-garden design, but dimensions and discharge arrangements need site-specific planning.
If you are planning one of these projects, a calculator quantity is your starting point, and your supplier or contractor can advise on drainage and base requirements for your site.
Common Gravel Calculator Mistakes#
- Mixing units. Entering depth in inches while length and width are in feet gives a wildly wrong result. Convert first or use a calculator that handles unit selection.
- Skipping the allowance. Gravel compacts and settles, so an exact calculation usually leaves you short.
- Ignoring the base layer. New driveways and paths often need a coarser base beneath the finish layer, which means two materials and two calculations.
- Using one depth everywhere. If part of an area is lower or needs more cover, calculate each section separately.
- Mixing tons and cubic yards. Confirm whether your supplier sells by weight or volume, and use that unit when you order.
- Forgetting delivery limits. Delivery is usually charged per trip, so a second small delivery is expensive.
- Choosing bags for a large project. Bagged gravel is convenient for small jobs but is generally much more expensive per cubic yard than bulk delivery.
Related Interior Tailor Calculators#
Gravel projects usually involve more than one material. These tools can help you plan the rest:
- Cubic Yard Calculator and Cubic Feet Calculator for converting volumes
- Square Footage Calculator for measuring irregular areas
- Paver Calculator for stone and paver patios or paths
- Topsoil Calculator, Mulch Calculator and Sod Calculator for surrounding planting areas
- Concrete Calculator for edging, footings or slabs
Frequently Asked Questions About Gravel Calculators#
How do I calculate how much gravel I need?
Multiply length by width by depth, all in feet, to get cubic feet, then divide by 27 for cubic yards. Multiply by your gravel’s tons per cubic yard to get tons, and add a small allowance for compaction.
How many tons are in a cubic yard of gravel?
It depends on the material, but a common planning figure is about 1.4 tons per cubic yard. Specific products range from roughly 1.35 to 1.5 tons or more, so confirm with your supplier.
How much area does one ton of gravel cover?
Using about 1.4 tons per cubic yard, one ton covers roughly 116 square feet at 2 inches deep and about 58 square feet at 4 inches deep, before any allowance for settling.
How much gravel do I need for a 10 x 20 ft driveway?
At 4 inches deep, that is about 2.5 cubic yards, or roughly 3.5 tons, and a little over 3.8 tons with a 10% allowance.
How deep should a gravel driveway be?
Most guidance points to about 4 to 6 inches, with heavier use and wetter climates favoring more depth. Ask a local supplier or contractor for your conditions.
Should I order gravel by the ton or by the cubic yard?
Order in the unit your supplier uses. Many sell by weight, others by volume. A good calculator gives you both so you can compare quotes.
How much extra gravel should I order?
About 10% is a common allowance for compaction and settling, and suppliers often suggest more for small orders. Round up to the next delivery quantity.
Is a gravel calculator exact?
No. It is an estimate based on the numbers you enter and typical material density. Moisture, stone size, surface preparation and compaction all change the amount you actually need.
Final Thoughts#
A gravel calculator takes the guesswork out of ordering, but the best results come from good inputs: accurate measurements, the right depth for the job, and the correct weight for your stone. Run your numbers, add a sensible allowance, and confirm everything with your supplier. When you are ready, open the Gravel Calculator and get your estimate in seconds.
