Gravel & Mulch Calculator
Calculate how much gravel, mulch, sand, or topsoil you need in cubic yards, tons, and bags.
Cubic Yards Needed comes from multiplying Length, Width, and Depth together (after converting Depth from inches to feet) and dividing by 27 to convert cubic feet into cubic yards -- because all three dimensions multiply into the same volume figure, nudging Length up 10% raises Cubic Yards Needed by the same 10% that nudging Width or Depth up 10% would. Material is a separate factor layered on top: it doesn't touch the volume calculation at all, but it sets the weight-per-cubic-yard and cost-per-cubic-yard used to compute Weight (Tons) and Est. Material Cost, and those figures swing far more from a material change than from an equivalent change in Length, Width, or Depth. Gravel and Pea Gravel weigh roughly 2,600-2,800 lbs per cubic yard, Sand runs about 2,700, Topsoil about 2,000, and Mulch only about 600 -- nearly a 5x spread -- so switching material at a fixed volume is the single biggest lever on both Weight (Tons) and Est. Material Cost. The bag counts (40 lb and 50 lb) are just that same total weight divided by bag size and rounded up, useful when buying bagged material instead of bulk delivery.
Inputs
Results
Cubic Yards Needed
1.85
How to Use This Calculator
- Enter the length and width of the area in feet.
- Set the depth in inches — typical mulch depth is 3 inches; gravel for driveways is 4–6 inches.
- Select the material type: gravel, mulch, sand, topsoil, or pea gravel.
- Read the cubic yards needed, total weight in tons, and estimated material cost.
- Use the bag count (40 lb or 50 lb bags) if ordering in bags from a store.
How the result changes with Length
| Length | Cubic Yards Needed |
|---|---|
| 101 | 9.35 |
| 351 | 32.5 |
| 650 | 60.19 |
| 900 | 83.33 |
What each input means
- Length
- Length of the shape or side.
- Width
- Width of the shape or side.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersLength = 20, Width = 10, Depth = 3, Material = 0 = 4 input(s) provided
- Calculate Cubic Yards NeededCubic Yards Needed1.85 = 1.85
- Calculate WeightWeight2.59 = 2.59
- Calculate 40 lb Bags40 lb Bags130 = 130
Engine last updated .
Frequently Asked Questions
Do length, width, and depth each affect the volume by the same amount?
Yes -- Cubic Yards Needed is Length times Width times Depth (converted to feet) divided by 27, so a given percentage increase to any one of the three dimensions raises the volume by that same percentage, whether the change comes from Length, Width, or Depth.
Why does changing material affect the weight so much more than volume changes?
Material sets a weight-per-cubic-yard figure that ranges from about 600 lbs for Mulch up to roughly 2,800 lbs for Gravel -- nearly a 5x spread -- so switching material at the same Cubic Yards Needed swings Weight (Tons) far more than an equivalent proportional change to Length, Width, or Depth would.
How is the estimated material cost calculated?
Est. Material Cost is Cubic Yards Needed multiplied by a cost-per-cubic-yard figure that depends on the selected Material, ranging from about $30 for Topsoil up to $55 for Pea Gravel. Because that per-yard rate varies by material more than volume typically varies from dimension changes alone, Material is the biggest driver of both cost and weight.
What's the difference between the 40 lb and 50 lb bag counts?
Both are the same total estimated weight divided by the bag size and rounded up to a whole bag -- 40 lb Bags simply divides by 40 and 50 lb Bags divides by 50. Use whichever matches the bag size your supplier actually sells to avoid buying more bags than needed.
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