How this instrument works
Underneath the name on the invoice, every bulk material order reduces to the same two-step conversion: multiply a footprint by a depth to get volume, then multiply that volume by the material's density to get weight. What changes from one material to the next is purely the density figure — the geometry of a pile of mulch and a pile of gravel is identical, but a cubic foot of one can weigh a third of what the other does.
This calculator is deliberately generic rather than built around one material's typical density, because "bulk material" covers an enormous weight range: gravel commonly runs around 105 lb/ft³, sand around 100, topsoil somewhere around 90-100 depending on moisture and compaction, and mulch as light as 40-50 lb/ft³ — nearly a threefold spread from lightest to heaviest. Rather than guess which material you mean and risk a wrong default, this tool asks you to enter the density directly, using your supplier's figure or a published range for your specific material.
The volume math itself doesn't depend on what you enter for density: length times width times depth (converted from inches to feet), divided by 27 to get cubic yards, since a cubic yard is 3×3×3 = 27 cubic feet. Weight in tons follows from multiplying that same volume by density and dividing by 2,000, the number of pounds in a US ton.
- Enter the length and width of the area to be covered, in feet.
- Enter the intended material depth, in inches.
- Enter the material's density in pounds per cubic foot — check a supplier spec sheet, or use a published typical range for your specific material (see the field's placeholder for rough starting figures).
- Read Volume in cubic yards and Weight in US tons.
Worked example — a 25 × 10 ft bed, 4 inches deep
A garden bed measures 25 by 10 feet, with a planned 4-inch material depth and a density of 100 lb/ft³ entered (a typical figure for sand or a comparable material). Volume = 25 × 10 × (4/12) = 83.333 cubic feet = 3.0864 cubic yards. Weight = 83.333 × 100 = 8,333.33 lb = 4.1667 tons.
Run the same 10 × 10 ft, 3-inch-deep bed with a much lighter mulch at 45 lb/ft³ instead: volume = 100 × 0.25 = 25 cubic feet = 0.9259 cubic yards; weight = 25 × 45 = 1,125 lb = 0.5625 tons — well under a third the weight of the same volume of sand, underlining why entering the correct density for your actual material matters more than the geometry step.
Questions
How do I convert cubic yards of material into tons?
Multiply cubic yards by 27 to get cubic feet, then multiply by the material's density in pounds per cubic foot, then divide by 2,000 to get US tons. This calculator does the whole chain from length, width, and depth in one pass, so you don't need a separate cubic-yards-to-tons step.
Why doesn't this calculator have a default density for a specific material?
Because "bulk material" spans a huge weight range — mulch can weigh under half what sand or gravel weighs per cubic foot — so any single default would be badly wrong for most materials it's applied to. This calculator asks for density directly instead, so you can use a supplier's actual figure or a published range for whatever material you're ordering.
What density should I use if I don't know my material's exact weight?
Published approximate ranges are a reasonable starting point: gravel around 105 lb/ft³, sand around 100, topsoil roughly 90-100 depending on moisture, and mulch around 40-50. These are typical figures that vary by source, moisture content, and compaction, so a supplier's own spec sheet or delivery ticket is more reliable than any general range if you have access to one.
How is this different from a gravel- or sand-specific calculator?
A material-specific calculator bakes in a typical density for that one material as a default, saving you a lookup for the common case. This calculator is the generic version — no material-specific default — built for anything that doesn't fit neatly into gravel, sand, or another named category, or for cases where you already know your exact material's density and want to skip guessing which named calculator is closest.
Does compaction change how much material I need to order?
Yes, often significantly — loose material delivered by the truck settles and compacts once spread and worked, sometimes losing 20-30% of its loose volume. If you're ordering to fill a specific compacted depth, some suppliers and contractors order extra loose volume to compensate; this calculator computes the straightforward volume-to-weight conversion and doesn't apply a compaction adjustment on its own.