Enter your dimensions, depth, and material type to estimate the right order size before you call a supplier.
Choose Material Type
Select Area Shape
Set Depth
Recommended depths: Mulch — 2–4 in for beds, 4–6 in near tree rings. Gravel — 2–3 in for decorative, 4–6 in for driveways. Compost — 2–3 in mixed in.
Preferred Output Unit
Scroll down for material guides, coverage charts, project tips, and volume formulas.
Step by step
How to use the calculator
Four quick inputs is all it takes. Here is what each one means and why it matters for an accurate estimate.
Choose your material
Select from wood mulch, gravel, rubber mulch, or compost. Each has different densities and coverage rates.
Enter your area
Measure length and width in feet, or pick the circle shape for round beds and features.
Set the depth
Use our recommended depths or enter your own. Depth is the biggest variable in how much material you need.
Pick your output unit
Get results in cubic yards, cubic feet, bags, or tons, whichever matches how your supplier sells.
Pro tip: always add a buffer
Add 10-15% to any calculator result before ordering. Material compacts when spread, some spills during delivery, and uneven ground consumes more than flat calculations suggest.
The math
How to calculate gravel volume yourself
The calculator handles the arithmetic, but it is useful to understand the formula if you need to estimate material on-site.
For a rectangular area, the formula is:
Depth (ft) = Depth (in) / 12
Cubic yards = Volume (cu ft) / 27
Example: A 12 x 8 ft area at 3 inches depth = 12 x 8 x (3/12) = 24 cu ft = 24/27 = 0.89 cubic yards.
For a circular area, use:
Volume (cu ft) = Area x Depth (ft)
Cubic yards = Volume / 27
Example: A 6 ft diameter tree ring at 4 inches depth works out to about 0.34 cubic yards.
Converting cubic yards to tons
Multiply cubic yards by the material weight factor. Gravel is about 1.4 t/yd³, wood mulch about 0.4, rubber mulch about 0.75, and compost about 0.7. Actual weights vary with moisture and material type.
Material guide
Which material do you need?
Each material has a different weight, coverage rate, and ideal use case. Choosing the right one up front prevents expensive do-overs.
Wood Mulch
Gravel / Stone
Rubber Mulch
Compost / Soil
Quick reference
Coverage per cubic yard by depth
One cubic yard covers different amounts of area depending on depth. Use this table as a quick sanity check against the calculator output.
These figures apply across gravel, mulch, compost, and rubber. Volume stays the same even though weight changes between materials.
| Depth | Coverage (sq ft) | Bags (2 cu ft) |
|---|---|---|
| 1" | 324 sq ft | ~18 bags (2 cu ft) |
| 2" | 162 sq ft | ~9 bags |
| 3" | 108 sq ft | ~6 bags |
| 4" | 81 sq ft | ~5 bags |
| 6" | 54 sq ft | ~3 bags |
Per 1 cubic yard. Bags estimated at 2 cu ft each.
Recommended depths by project type
Project guides
Common landscaping projects
Every project has its own quirks. Here is what experienced landscapers watch for in the most common jobs.
Driveway gravel
Gravel driveways are one of the most cost-effective surfacing options, typically running $1-$3 per square foot compared to $3-$7 for asphalt. Getting the volume right upfront saves multiple delivery fees.
- Plan for a 4-inch base layer of compacted angular crushed stone (#57 or #411).
- Add a 2-inch top-dress layer of smaller stone for a cleaner finish.
- Order 10-15% extra to account for compaction loss and edge overspill.
- A fabric weed barrier underneath extends driveway life significantly.
Recommended depth
Base: 4-6 in / Top dress: 2 in
Best material
Crushed stone, crusher run, or pea gravel
Garden bed mulch
Mulching garden beds is one of the highest-ROI tasks in landscaping. It reduces watering needs, suppresses weeds for a full season, and improves soil health as it breaks down.
- Apply 2-3 inches for established beds and 4 inches for first-year weed suppression.
- Keep mulch 2-3 inches away from plant stems to prevent rot.
- Refresh mulch annually instead of piling new layers on top of decomposed material.
- Hardwood bark mulch lasts longer than shredded softwood or pine straw.
Recommended depth
2-4 in for beds / 4-6 in near tree rings
Best material
Hardwood bark, wood chips, or pine straw
Drainage and French drains
Proper drainage gravel prevents water pooling, foundation damage, and erosion. The right stone size and volume matters because too little backs water up and too much wastes money.
- Use #57 washed stone for most French drain applications.
- Trench depth is typically 18-24 inches and width is 12-18 inches.
- Line the trench with landscape fabric to prevent soil migration into the gravel.
- Calculate the trench as a rectangle: length x width x depth, then divide by 27 for cubic yards.
Recommended depth
Fill trench completely, typically 18-24 in deep
Best material
#57 washed stone or river rock
Playground rubber mulch
Playground surfacing is not just aesthetic. The required depth depends on fall height and safety guidelines, so getting the quantity right matters.
- Use 6 inches of depth for equipment up to 7 feet of fall height.
- Use 9 inches for equipment up to 10 feet of fall height.
- Rubber mulch compacts less than wood mulch, so it needs less top-up over time.
- Use a border or edging system to keep rubber mulch contained.
Recommended depth
6 in minimum / 9 in for higher equipment
Best material
Rubber mulch
Before you buy
How to order the right amount
Getting your order right on the first call saves money and time. Suppliers sell gravel and mulch in different units, so you need to match the estimate to the quote.
Bulk vs. bagged: Bulk delivery is usually cheaper per unit once you need more than 2-3 cubic yards. Below that, bagged material can be more convenient.
Delivery minimums: Many bulk suppliers have a 1-2 cubic yard minimum. Ask whether they charge partial-yard fees before ordering.
Measure twice
Re-measure your area before you call the supplier. A 10% error on a 10-yard order is a full extra yard.
Add 10-15% buffer
Material compacts, some is lost at edges, and ground is rarely perfectly flat.
Ask how it is sold
Confirm whether the quote is by cubic yard, ton, or bag so you can match units correctly.
Schedule delivery wisely
If the project spans multiple weekends, decide whether material can be stored on-site safely.
FAQ
Frequently asked questions
Common questions about calculating gravel, mulch, and landscaping material volumes.
How many cubic yards of gravel do I need for a driveway?
A standard two-car driveway (20 ft x 20 ft) at 4 inches deep needs about 5 cubic yards of gravel. Use the calculator above, enter your actual dimensions, and set depth to 4 inches for a solid base layer.
How deep should gravel be for a driveway?
For a new driveway base, plan for 4-6 inches of compacted gravel. Decorative top-dress layers can be 2-3 inches. If you are laying over existing gravel, 2 inches is usually enough to refresh the surface.
How many bags of mulch do I need for a garden bed?
A 2 cubic foot bag of mulch covers about 12 square feet at 2 inches deep. For a 100 square foot garden bed at a 3-inch depth, you would need roughly 13 bags. The calculator converts automatically when you select bags as the output unit.
What is the difference between cubic yards and tons for gravel?
Cubic yards measure volume, while tons measure weight. For gravel, one cubic yard weighs roughly 1.4 tons, though crushed stone can be closer to 1.5 tons. Some suppliers sell by the ton and others by the yard, so the calculator shows both.
How much does a cubic yard of mulch cover?
One cubic yard of mulch covers 324 square feet at 1 inch deep, 162 square feet at 2 inches, or 108 square feet at 3 inches. Three inches is usually the sweet spot for weed suppression without suffocating plant roots.
How do I calculate gravel for a circular area?
Use the formula: volume = pi x radius squared x depth, then divide by 27 to convert cubic feet into cubic yards. A 10-foot diameter circle at 3 inches deep works out to about 0.73 cubic yards. The calculator handles that automatically when you select the circle shape.
How much does a yard of gravel weigh?
It depends on the gravel type. Pea gravel is about 1.4 tons per yard, crushed limestone about 1.5, river rock about 1.35, and decomposed granite about 1.4. The calculator uses a standard 1.4 tons per yard estimate for gravel.
Can I use this calculator for compost and topsoil?
Yes. Select Compost / Soil from the material selector. Compost weighs roughly 1,000 to 1,400 pounds per cubic yard depending on moisture content, and the calculator adjusts the weight estimate accordingly.
Related calculators and guides
Mulch calculator
CalculatorCoverage estimates for wood, bark, and rubber mulch by bag or yard.
Gravel calculator
CalculatorA broader gravel guide for driveways, paths, decorative stone, and tonnage planning.
Gravel vs mulch
GuideCompare long-term cost, upkeep, and best use cases before you choose a material.