Volume to Weight Calculator
Results update as you type, there is no submit button.
Enter a volume in cubic feet, pick a material from the dropdown, or enter a custom density if yours isn't listed, and this calculator returns the total weight in pounds and kilograms. Built for checking a load against a vehicle, trailer or floor's weight limit before you commit to hauling it.
Why Volume Alone Never Tells You the Weight
Volume to weight
Weight (lb) = Volume (ft³) × Density (lb/ft³)
The density figure is the missing number that turns a space measurement into a weight one.
Volume describes how much space something occupies; weight depends entirely on the density of whatever fills that space, and densities vary enormously. A cubic foot of cured concrete weighs about ten times what a cubic foot of bark mulch weighs, even though both are exactly one cubic foot. The table below carries the same density figures used across this site's other calculators, nothing here contradicts a number you'd see on the gravel or soil pages.
Reference Densities
| Material | Density (lb/ft³) | Weight of 10 ft³ |
|---|---|---|
| Water | 62.4 | 624 lb |
| Concrete (cured) | 150 | 1,500 lb |
| Sand (dry) | 100 | 1,000 lb |
| Wet soil | 100 | 1,000 lb |
| Gravel | 95 | 950 lb |
| Dry soil | 75 | 750 lb |
| Bark mulch | 15 | 150 lb |
Three Things That Move These Numbers
Moisture is the biggest swing factor, soil, sand and gravel all gain weight after rain as water fills the air gaps between particles, sometimes by twenty percent or more. Compaction is the second: the same material weighs more per cubic foot once it's been tamped down, because compaction squeezes out air without removing any mass. Particle size is the third, coarse aggregate traps more air between pieces than fine material does, so it's lighter per unit of volume even when the stone itself is exactly as dense.
These three factors are why the density table above should be read as a starting point, not a guarantee, if you know your specific material's density differs from the reference figure, the calculator's custom-density option lets you swap in the real number. Bark mulch is the clearest illustration of how far density can swing: at just 15 lb/ft³, the same truck that can barely move a couple cubic yards of gravel could carry ten times that volume of mulch without approaching its weight limit.
Worked Example: A Trailer Load of Gravel
A trailer holding 40 cubic feet of gravel:
40 ft³ × 95 lb/ft³ = 3,800 lb
That's 1.9 tons, check it against the trailer's rated payload before loading.
This is exactly the calculation worth running before any load that's close to a weight limit, whether it's a trailer, a pickup bed, or a shipping pallet that a freight carrier will bill by weight if it turns out heavier than its volume suggested.
Vehicle and Trailer Payload Ratings
Every vehicle and trailer has a rated payload, the maximum weight it's built to carry safely, printed on a manufacturer's plate or listed in the owner's manual, and it's a real engineering limit, not a rough suggestion. Exceeding it strains suspension, brakes and tires in ways that aren't always obvious immediately but that raise real safety and liability concerns, particularly on trailers, which don't always show the warning signs of being overloaded the way a sagging truck bed does. Before loading anything calculated on this page, check the volume's weight against the specific vehicle or trailer's rated payload, not against a general sense of "this looks like it'll fit", a small trailer can look like it's carrying a modest load of gravel or soil while actually being significantly over its rated limit, precisely because dense materials pack a lot of weight into a deceptively small-looking volume.
Multiple smaller loads within the rated limit, rather than one load that exceeds it, is always the safer choice when a calculated weight comes in close to or over a vehicle's rating, the extra trip costs time, but overloading costs far more if something fails.
Floor Loading for Indoor Storage
The same weight-versus-limit logic applies indoors, where it's easy to forget it matters at all. Upper floors, decks and some garage floors have a rated load capacity per square foot, and stacking dense material, stone, soil, stacked lumber, filled water containers, in one concentrated area can exceed that rating even when the total weight would be perfectly fine spread across an entire room. This calculator's weight output combined with the footprint the material actually occupies (not the whole room) is the right comparison to make against a floor's load rating, which is usually expressed as pounds per square foot rather than a single total figure.
When to Weigh Instead of Calculate
This calculator's density figures are useful planning estimates, but for a load where the exact weight genuinely matters, right at a legal axle limit, or a delivery you're being billed by weight for, a certified scale reading beats any calculated estimate, since real material never matches a reference density exactly. Many aggregate and landscaping suppliers weigh loaded trucks on-site as a matter of course specifically because moisture and compaction vary too much load to load for volume alone to be billed against reliably. Treat this page's figures as the number to plan and budget around before a delivery, and a certified weight as the number to trust once material is actually loaded and billed.
Combining Materials of Different Densities
A job that mixes materials, a base layer of gravel under a top layer of soil, say, needs each layer's weight calculated separately with its own density rather than averaging the two, since averaging assumes an even blend that doesn't reflect how the materials are actually layered or loaded onto a vehicle. Calculate each material's volume and weight independently using this page, then add the weight totals together for a combined figure, this is the only way to get an accurate total when a single load or delivery carries more than one material at different densities.
A Quick Sanity Check
Because most everyday materials fall somewhere between about 15 and 150 lb/ft³, a calculated weight wildly outside that range for a household-scale volume is worth double-checking. If a modest few-cubic- foot quantity comes out at several thousand pounds, the density value was likely entered as a per-yard or per-ton figure rather than per cubic foot; if it comes out surprisingly light for a dense material like gravel or concrete, check that the correct material was selected rather than left on a lighter default.
Frequently Asked Questions
Why do two materials with the same volume weigh such different amounts?
Weight depends on density, how tightly a material's particles pack together, not just on how much space it fills. A cubic foot of concrete weighs ten times what a cubic foot of bark mulch does because concrete has almost no air gaps and mulch is mostly them.
Does moisture really change a material's weight that much?
Yes, soil, sand and gravel can gain twenty percent or more in weight after rain, since water fills the air gaps between particles. If you're near a vehicle payload limit, always check weight after a wet spell, not just from a dry-density chart.
Why is compacted material heavier than the same loose material?
Compaction pushes particles closer together, squeezing out the air gaps that were taking up volume without adding weight, the same mass now occupies less space, so density (and therefore weight per cubic foot) goes up. A load that measured a certain volume when delivered loose can weigh noticeably more once it settles or gets driven over.
How do I check a trailer or vehicle load against its weight limit?
Calculate the material's volume, multiply by the density figure on this page (or a custom density if you know your specific material), and compare the resulting weight against your vehicle or trailer's rated payload, not just against how full the bed or trailer looks.