Gravel Calculator
Estimate gravel volume in cubic yards, convert that volume to tons using a bulk-density value, and optionally estimate material cost. Choose a rectangular or circular area, enter the planned depth, and use a supplier-provided density whenever you have one.
For a rectangular area, cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27. For example, 10 × 10 ft at 3 inches deep is about 0.93 cubic yards. Converting that volume to tons requires the bulk density of the specific material and condition you plan to buy.
Area × (Depth ÷ 12) ÷ 27 = cubic yardsTurn Area and Depth Into an Order Estimate
Calculate geometric volume
Convert the footprint and planned depth into cubic feet, then divide by 27 to express the result in cubic yards.
Convert volume to weight
When you enter a bulk density in pounds per cubic yard, the calculator converts cubic yards to tons using 2,000 pounds per U.S. short ton.
Use rectangular or circular areas
Rectangular mode uses length × width. Circular mode uses π × radius², which is useful for round beds and similar areas.
Keep density adjustable
FHWA references show granular-material unit weight varies with grading, moisture and compaction. A supplier-specific value is therefore more reliable than a universal gravel density.
How the Gravel Calculator Works
The volume calculation is independent of material type. Density is needed only when converting that volume into an estimated weight.
1. Find the area
Rectangle: length × width. Circle: π × (diameter ÷ 2)².
2. Convert depth to feet
Because the input depth is in inches, divide it by 12 before multiplying by the area.
3. Convert cubic feet to cubic yards
Divide cubic feet by 27 because one cubic yard contains 27 cubic feet.
4. Estimate tons and cost
tons = cubic yards × lb/yd³ ÷ 2,000. If a price per ton is entered, estimated material cost is tons × price.
Cubic Yards Needed per 100 Square Feet
This table shows geometric volume only. It does not assume a material density or recommend a project depth.
| Depth | Cubic feet | Cubic yards |
|---|---|---|
| 2 in | 16.67 | 0.62 |
| 3 in | 25.00 | 0.93 |
| 4 in | 33.33 | 1.23 |
| 6 in | 50.00 | 1.85 |
Gravel Calculator Examples
The density values below are illustrative inputs, not universal material specifications. Use your supplier’s value for an actual order.
20 × 10 ft rectangular area at 3 inches
Takeaway: the 1.85 yd³ volume is fixed by geometry; the 2.50-ton result depends on the example density.
12 ft diameter circle at 4 inches
Takeaway: circular mode uses π × radius² before applying the same depth and volume conversions.
100 sq ft area at 2 inches
Takeaway: this excludes delivery, minimum orders, tax and site work; price and density are illustrative inputs.
Gravel Estimating Mistakes to Avoid
Mixing inches and feet
The depth field is in inches. The calculator divides by 12 before combining depth with an area measured in square feet.
Assuming one density fits every aggregate
FHWA data show unit weight changes with material grading and condition. Supplier-specific bulk density is preferable for order planning.
Confusing loose and compacted density
A loose delivered aggregate and a compacted base are not necessarily represented by the same unit weight. Use a density that matches the quantity you are trying to estimate.
Treating material cost as the delivered project price
The calculator multiplies estimated tons by the price you enter. Delivery, minimum orders, tax, labor and site preparation are separate unless your quoted price already includes them.
Gravel Calculator FAQ
How do I calculate cubic yards of gravel?
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How does the calculator convert cubic yards to tons?
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What density should I enter?
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How deep should gravel be?
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Should I automatically add 10% extra?
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What does the cost estimate include?
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About This Calculator
Built and maintained by Umer Farooq, founder and developer of CalcsDone. The page shows the geometry, unit conversions, adjustable density input and worked examples so the estimate can be checked independently. See the CalcsDone Methodology or contact us if you spot an issue.
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Gravel Calculator References
- Federal Highway Administration — Geotechnical Aspects of Pavements, Chapter 5
- Federal Highway Administration — Strength Characterization of Open-Graded Aggregates
- Federal Highway Administration — Granular Base Application Description
- U.S. Geological Survey — Construction Sand and Gravel Statistics and Information
- CalcsDone Methodology