This gravel calculator estimates how much gravel you need from length, width, and depth. It converts the fill volume into cubic yards and helps you plan tons, bags, and material cost for driveways, paths, and garden beds. Use it for quantity planning before you order bulk or bagged stone.
Homeowners, landscapers, and DIY builders reach for a gravel calculator when a supplier asks for cubic yards or when bag labels list coverage by depth. The tool keeps the math transparent so you can compare bulk delivery against bagged product without guessing.
Who should use this gravel calculator
Use this page when you are covering a rectangular driveway apron, a walking path, a patio base, or a raised bed border. It is also useful when a quote lists price per ton or per cubic yard and you need a consistent volume estimate first.
If your area is an L shape or has multiple beds, run each rectangle separately and add the cubic yards. Do not force one average depth across sections that need different bases.
How to use the gravel calculator
- Enter length and width in feet for the area you will cover.
- Enter depth in inches. Typical driveway base layers often sit around 4 inches, while decorative top dress layers can be thinner.
- Read the cubic yard estimate from the tool.
- Apply a density factor if you need approximate tons for a supplier that sells by weight.
- Add a waste or overage allowance of about 5 to 10 percent when ordering for irregular edges.
How gravel volume is calculated
Convert depth from inches to feet by dividing by 12. Multiply length × width × depth in feet to get cubic feet. Divide cubic feet by 27 to get cubic yards.
Volume (yd³) = length (ft) × width (ft) × (depth (in) ÷ 12) ÷ 27
Approximate weight uses a material density. Many crushed stone estimates land near 1.3 to 1.5 tons per cubic yard, but products vary. Always confirm density with your supplier rather than treating any web average as a guarantee.
Worked driveway gravel example
Suppose a driveway section is 30 ft long and 12 ft wide with a 4 inch depth.
Depth in feet = 4 ÷ 12 = 0.333 ft.
Cubic feet = 30 × 12 × 0.333 ≈ 120 ft³.
Cubic yards = 120 ÷ 27 ≈ 4.44 yd³.
With a 10 percent overage, order about 4.9 cubic yards. If density is about 1.4 tons per cubic yard, weight is roughly 6.2 tons before rounding to the supplier delivery increment.
| Input | Value |
|---|---|
| Length | 30 ft |
| Width | 12 ft |
| Depth | 4 in |
| Volume | ~4.44 yd³ |
| With 10% overage | ~4.9 yd³ |
Path and garden bed examples
A 40 ft × 3 ft path at 2 inches deep is much smaller: depth = 2 ÷ 12 ≈ 0.167 ft, volume ≈ 40 × 3 × 0.167 ÷ 27 ≈ 0.74 yd³. Bagged product may be cheaper for that size than a bulk minimum delivery.
A 10 ft × 8 ft garden bed at 3 inches is about 0.74 yd³ as well. Run both beds separately if depths differ, then add the yards before you price bulk versus bags.
Tons, bags, and cost planning
Suppliers may sell by the ton, by the cubic yard, or by the bag. Convert to one unit before you compare prices. Include delivery fees and minimum order charges. A low unit price can lose if delivery has a high minimum.
Bagged gravel lists coverage by depth on many labels. If a bag covers 0.5 cubic feet at your depth, divide total cubic feet by 0.5 and round up. Keep bag size and depth assumptions written next to the total so reorders stay consistent.
Loose volume versus compacted base
Fresh gravel can settle after compaction and traffic. If you are building a structural base, ask whether the quote assumes loose fill or compacted thickness. Ordering only the compacted depth with no overage is a common reason projects run short.
Choosing gravel type for the job
Driveway base stone, pea gravel, and decorative river rock behave differently. Angular crushed stone locks better under tires. Rounded decorative stone looks softer in beds but can migrate on slopes. Match product to use case before you lock a density or bag coverage assumption.
Drainage layers and French drain stone also need correct gradation. Volume math still applies, but the wrong stone size can clog fabric or fail to drain even when the yardage is correct.
Measuring tips that keep orders accurate
Measure length and width at the surface you will actually cover, not the property line sketch. For tapered driveways, average the widths or split into two rectangles. Write the depth target next to each section so helpers do not rake one area thin and another thick.
If you already have an old gravel layer, decide whether you are topping up or rebuilding. Top-ups need less depth. Rebuilds need full base thickness again.
Common gravel calculator mistakes
- Mixing inches and feet in the depth field
- Using one depth for base and top dress layers
- Ignoring delivery minimums when comparing bulk to bags
- Treating a generic tons-per-yard factor as exact for every stone type
- Forgetting irregular edges and rake-out waste
Limitations
Results are planning estimates. Real products vary by density, moisture, and gradation. Sloped sites, curved edges, and geotextile thickness can change the amount you need. Confirm final quantities with your supplier before large orders.
Ordering bulk versus bags
Bulk delivery often wins on large driveways once you clear the supplier minimum. Bags win on small paths when delivery fees erase the bulk discount. Convert both quotes to cost per cubic yard before you decide.
Depth choices that change the order
A decorative top dress may need only one to two inches. A driveway base often needs several inches of compacted stone. Write the target compacted depth on your plan, then add overage for edges and compaction loss.
Working with irregular shapes
Split curves and L shapes into rectangles. Add the cubic yards. If one section is thinner decorative stone on top of a thicker base, calculate each layer alone so the supplier ticket matches the work.
For related unit and percent checks while you plan materials, try the unit converter or the percentage calculator.