Cubic Feet to Pounds Converter
Convert cubic feet to pounds using material density. Pick what fills the space — water, kitchen staples like flour, sugar, and honey, or dry sand, gravel, topsoil, and concrete — enter cubic feet, and get pounds, kilograms, and gallons.
Example: with Volume in cubic feet 1 · Material Water (1.00 g/mL) → Pounds: 62.43 lb.
- In kilograms28.32 kg
- Volume in gallons7.48 US gallons
Computed by the calculator below using its default values. Change any input to see your own numbers.
lb = cu ft × 62.428 × density (g/mL). One cubic foot of water is 62.43 lb; sand roughly 100 lb; concrete about 150 lb.
62.4 pounds per cubic foot of water — everything else scales from there
A cubic foot holds 28.3168 liters, so its weight is that volume times density. Water at 1 g/mL comes to 62.43 lb — the benchmark figure aquarium builders learn the hard way, since a modest 50-gallon tank holds about 417 lb of water. Multiply water's number by a material's density and you have its per-cubic-foot weight: dry sand at 1.60 lands near 100 lb, concrete at 2.40 near 150 lb.
The materials in the list are the ones people actually price by the cubic foot: bagged soil, sand, gravel, and ready-mix concrete. A common surprise is moisture — wet sand can weigh 15 to 20 percent more than dry, and saturated topsoil far more than the 76 lb dry figure. When a floor-load or truck-bed limit is at stake, round densities up, not down.
How it’s calculated
Liters = cu ft × 28.316846592 (exact, from 1 ft = 0.3048 m); kg = liters × density (g/mL); pounds = kg ÷ 0.45359237 (exact). Equivalent shortcut: lb = cu ft × 62.428 × density. Gallons = cu ft × 7.48052. Densities: water 1.00, milk 1.03, vegetable oil 0.92, flour 0.53, sugar 0.85, honey 1.42, butter 0.955, dry sand 1.60, gravel 1.68, dry topsoil 1.22, concrete 2.40.
Densities are approximate — moisture, compaction, and aggregate mix swing bulk materials 15 percent or more, so treat results as planning estimates, not scale weights.
Weight of one cubic foot, by material
| Material | Density (g/mL) | Pounds per cu ft |
|---|---|---|
| Water | 1.00 | 62.4 lb |
| Vegetable oil | 0.92 | 57.4 lb |
| All-purpose flour | 0.53 | 33.1 lb |
| Granulated sugar | 0.85 | 53.1 lb |
| Honey | 1.42 | 88.6 lb |
| Dry topsoil | 1.22 | 76.2 lb |
| Dry sand | 1.60 | 99.9 lb |
| Concrete | 2.40 | 149.8 lb |
lb per cu ft = density × 62.428; densities are approximate published bulk values (dry, loose fill).
Common mistakes
- Using water's 62.4 lb for soil or sand — bulk materials run 20 to 140 percent heavier.
- Pricing wet material with dry density; rain-soaked sand or soil adds 15 percent or more.
- Confusing cubic feet with square feet — you need depth to get a volume before any weight math.
- Ignoring compaction: a truck bed of loose mulch settles, but packed gravel weighs what the density table says regardless of how fluffy it looked.
Frequently asked questions
How many pounds is 1 cubic foot of water?
62.43 lb. A cubic foot is 28.3168 liters and water weighs about 1 kg per liter, giving 28.32 kg, which converts to 62.43 pounds.
What is the formula for cubic feet to pounds?
Pounds = cubic feet × 62.428 × density in g/mL. For 2 cu ft of dry sand at 1.60: 2 × 62.428 × 1.60 = 199.8 lb.
How much does a cubic foot of soil or sand weigh?
Roughly 76 lb for dry loose topsoil and 100 lb for dry sand, rising sharply with moisture. Bagged products often state weight — a typical 1.5 cu ft bag of topsoil runs about 80 to 115 lb depending on moisture.
Why does the converter also show gallons?
Because one cubic foot equals 7.48 US gallons, and tank and aquarium problems usually start in cubic feet but end in gallons. It is the same volume expressed in a friendlier unit.