Cubic Feet to Pounds Calculator
Enter a volume in cubic feet and select your material to get the weight in pounds instantly. You can also enter pounds and solve for cubic feet. Choose from over 30 preset materials - concrete, sand, soil, steel, water, wood, and more - or type in a custom density. Switch the density input between lb/ft3, kg/m3, and g/cm3 so you can paste any spec-sheet value without converting by hand.
How to convert cubic feet to pounds
Volume and weight measure different physical quantities, so you cannot convert one to the other without knowing the density of the material. Density is the mass packed into each unit of volume. The conversion formula is straightforward: Weight (lbs) = Volume (ft3) x Density (lb/ft3). For example, 10 cubic feet of concrete, which has a typical density of 150 lb/ft3, weighs 10 x 150 = 1,500 lbs. For the reverse - finding volume from weight - rearrange the formula: Volume (ft3) = Weight (lbs) / Density (lb/ft3). This calculator handles both directions. Select the material (or type a custom density), choose whether you want to solve for pounds or for cubic feet, then enter the known value.
Why material density matters so much
The same volume of different materials can weigh wildly different amounts. One cubic foot of fresh mulch weighs about 18 lbs, while one cubic foot of steel weighs 490 lbs - a 27-fold difference. Even within a single material category, density varies. Dry sand weighs about 100 lb/ft3, but the same sand fully saturated with water weighs around 130 lb/ft3. Compacted topsoil is denser than loose topsoil. Lightweight concrete mixes weigh roughly 110 lb/ft3, while a standard reinforced mix is closer to 150 lb/ft3. Always use the density value that matches your actual material condition - dry, wet, compacted, or loose. The reference table below lists typical densities for over 25 common materials.
Practical applications: construction, landscaping, and shipping
Volume-to-weight conversion comes up constantly in practical work. In construction and landscaping, you typically order materials by the cubic yard (1 cubic yard = 27 cubic feet), but trucks and equipment have weight limits rated in tons. Knowing how many pounds a given volume weighs lets you confirm a truck will not be overloaded before the order arrives. A standard tandem-axle dump truck carries about 12-15 cubic yards of gravel; at 105 lb/ft3, that is 34,020 to 42,525 lbs (17 to 21 short tons), well within the typical 20-ton payload limit. In shipping and freight, carriers charge by whichever is greater - actual weight or dimensional weight. If you know the cubic footage of a shipment and the material density, you can compare the two and predict whether you will be billed by weight or by size.
Entering density from a spec sheet in different units
Material spec sheets often list density in kg/m3 (SI units) or g/cm3 (used in chemistry and geology) rather than lb/ft3. This calculator accepts all three units - select the correct one from the "Density unit" dropdown and enter the value directly from your spec sheet. The conversion factors are: 1 kg/m3 = 0.062428 lb/ft3, and 1 g/cm3 = 62.428 lb/ft3. For example, if a spec sheet lists concrete density as 2,400 kg/m3, you can either select "kg/m3" and type 2,400, or convert manually: 2,400 x 0.062428 = 149.8 lb/ft3, which matches the 150 lb/ft3 preset in this calculator.
Common material densities (lb/ft3)
| Material | Density (lb/ft3) | Category | Notes |
|---|---|---|---|
| Water (fresh) | 62.43 | Liquids | Standard reference at 62 F |
| Water (saltwater) | 64 | Liquids | Average ocean salinity |
| Gasoline | 46.7 | Liquids | Varies with grade and temp |
| Diesel fuel | 53.1 | Liquids | Standard diesel |
| Mulch (bark) | 18 | Landscaping | Dry bark mulch |
| Compost | 45 | Landscaping | Finished compost |
| Snow (fresh) | 5 | Other | Freshly fallen snow |
| Snow (packed) | 20 | Other | Settled / compacted snow |
| Ice | 57.4 | Other | Pure water ice |
| Wood - Cedar | 23 | Wood | Dry, kiln-dried |
| Wood - Pine | 30 | Wood | Dry, kiln-dried |
| Wood - Oak | 47 | Wood | Dry, kiln-dried |
| Topsoil (loose) | 75 | Construction | Uncompacted, typical garden soil |
| Topsoil (compacted) | 100 | Construction | Mechanically compacted |
| Clay (dry) | 100 | Construction | Dry natural clay |
| Clay (wet) | 120 | Construction | Saturated clay |
| Sand (dry) | 100 | Construction | Fine to coarse dry sand |
| Sand (wet) | 130 | Construction | Saturated sand |
| Gravel (dry) | 105 | Construction | Mixed aggregate |
| Gravel (wet) | 125 | Construction | Saturated gravel |
| Concrete (lightweight) | 110 | Construction | Lightweight structural mix |
| Concrete (cured) | 150 | Construction | Standard reinforced concrete |
| Asphalt | 142 | Construction | Hot-mix, compacted |
| Brick (common) | 120 | Construction | Standard clay brick |
| Aluminum | 169 | Metals | |
| Iron (cast) | 450 | Metals | |
| Steel | 490 | Metals | Structural steel |
| Copper | 559 | Metals | |
| Lead | 708 | Metals |
Typical densities used for construction, landscaping, and industrial calculations. Actual values vary with moisture content, compaction, and temperature.
Frequently asked questions
How many pounds is 1 cubic foot of concrete?
One cubic foot of standard cured concrete weighs approximately 150 pounds (about 68 kg). Lightweight concrete mixes used for insulation or reducing structural load typically weigh 110 lb/ft3. The exact number depends on the water-cement ratio, aggregate type, and how much reinforcement is present, but 150 lb/ft3 is the industry standard value used in most structural calculations.
How much does 1 cubic foot of water weigh?
One cubic foot of fresh water at 62 degrees Fahrenheit weighs 62.43 pounds (28.32 kg). This is one of the most useful reference values in engineering because it is derived directly from water's density of 1,000 kg/m3 (or 1 g/cm3). Saltwater is slightly denser, averaging about 64 lb/ft3 depending on salinity.
How many pounds is 1 cubic foot of sand?
Dry sand weighs roughly 100 pounds per cubic foot. Wet or saturated sand is heavier at around 130 lb/ft3 because water fills the air voids between grains. Compaction also increases density. For ordering purposes, dry sand is typically sold by weight or by the cubic yard (27 ft3), so 1 cubic yard of dry sand weighs approximately 2,700 lbs (1.35 short tons).
How many pounds is 1 cubic foot of soil?
Loose topsoil weighs about 75 pounds per cubic foot. Compacted or tightly packed topsoil is heavier, around 100 lb/ft3. If the soil is wet or clay-rich it can be even heavier. Landscapers commonly order topsoil by the cubic yard; at 75 lb/ft3 one cubic yard (27 ft3) of loose topsoil weighs about 2,025 lbs, or just over one short ton.
How do I convert cubic feet to pounds for gravel?
Multiply the volume in cubic feet by the density of gravel. Dry gravel typically weighs 105 lb/ft3, and wet gravel weighs about 125 lb/ft3. For example: 5 cubic feet x 105 lb/ft3 = 525 lbs (dry), or 5 x 125 = 625 lbs (wet). One cubic yard of dry gravel (27 ft3) weighs about 2,835 lbs - slightly over one and a half short tons.
Can I convert pounds back to cubic feet?
Yes. Rearrange the weight formula: Volume (ft3) = Weight (lbs) / Density (lb/ft3). If you have 3,000 lbs of concrete with a density of 150 lb/ft3, the volume is 3,000 / 150 = 20 cubic feet. In this calculator, switch the "Solve for" dropdown to "Cubic feet (enter pounds)" and enter your weight to get the volume automatically.
What is the formula for cubic feet to pounds?
Weight (lbs) = Volume (ft3) x Density (lb/ft3). The density must match the material and its condition (dry, wet, compacted). For the reverse: Volume (ft3) = Weight (lbs) / Density (lb/ft3). Because density can be specified in other units (kg/m3 or g/cm3), use the conversion factor 1 kg/m3 = 0.062428 lb/ft3 or 1 g/cm3 = 62.428 lb/ft3 to convert before applying the formula.