Mass per volume density.
Pounds per Cubic foot to Grams per Cup Converter — lb/ft3 to g/cup
Convert Pound per Cubic foot (lb/ft3) to Gram per Cup (g/cup) using the exact conversion factor (1 pound per cubic foot = 3.789780001 gram per cup). See the formula, worked examples, conversion table, and common uses.
Pounds per Cubic foot to Grams per Cup converter
Converter
Density Converter
Convert thousands of mass-per-volume density combinations for science, engineering, agriculture, and fluids.
Context values
Some unit families need one extra value for a physically accurate result.
Mass per volume density.
Result = input x 16.01846337 / 4.226752838.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Pounds per Cubic foot to Grams per Cup
Pound per Cubic foot and Gram per Cup both measure density — mass per unit volume — a property used to identify materials, check manufacturing quality, and predict whether something floats or sinks. As a fixed reference point, water has a density of exactly 1000 kg/m³ (1 g/cm³, 1 g/mL) at its temperature of maximum density, which is why many density figures in science and engineering are quoted relative to water. Pound per Cubic foot is most often used for us construction material density specs (concrete, soil, lumber, insulation).
Formula
grams per cup = pounds per cubic foot × 3.78978000109
This factor comes from each unit's defined relationship to the category's base unit: 1 pound per cubic foot equals 16.018463374 base units, and 1 gram per cup equals 4.22675283773 base units, so dividing one by the other gives the direct pound per cubic foot-to-gram per cup factor of 3.78978000109.
Simple example
1 lb/ft3 × 3.789780001 = 3.789780001 g/cup
1 pound per cubic foot = 3.789780001 grams per cup.
Real-world example
1,000 lb/ft3 × 3.789780001 = 3,789.780001 g/cup
1,000 pounds per cubic foot = 3,789.780001 grams per cup.
Conversion table
| Pound per Cubic foot (lb/ft3) | Gram per Cup (g/cup) |
|---|---|
| 0.1 lb/ft3 | 0.3789780001 g/cup |
| 1 lb/ft3 | 3.789780001 g/cup |
| 10 lb/ft3 | 37.89780001 g/cup |
| 100 lb/ft3 | 378.9780001 g/cup |
| 1,000 lb/ft3 | 3,789.780001 g/cup |
| 10,000 lb/ft3 | 37,897.80001 g/cup |
Reverse conversion: Gram per Cup to Pound per Cubic foot
3.789780001 g/cup × 0.2638675595 = 1 lb/ft3
3.789780001 grams per cup = 1 pounds per cubic foot.
pounds per cubic foot = grams per cup × 0.263867559519
For a page dedicated to this direction, see Gram per Cup to Pound per Cubic foot.
Understanding the Pound per Cubic foot
Pound per Cubic foot (lb/ft3) measures density. The US customary unit for expressing density, commonly used in construction and engineering material specifications. It is classified as a US customary density unit.
Where it's used: United States (construction, engineering, materials specifications)
Uses of the Pound per Cubic foot today
- US construction material density specs (concrete, soil, lumber, insulation)
- US engineering material property tables
- Bulk material handling and shipping weight estimates
Understanding the Gram per Cup (g/cup)
Mass per volume density.
Pound per Cubic foot — sources
- NIST Handbook 44 — General tables of units including US customary density measures.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many grams per cup are in 1 pound per cubic foot?
1 pound per cubic foot equals 3.789780001 grams per cup, using the exact defined conversion factor rather than an estimate.
How do I convert pound per cubic foot to gram per cup?
Multiply the pound per cubic foot value by 3.789780001. The converter above does this instantly to whatever precision you set.
How do I convert gram per cup back to pound per cubic foot?
Use the reverse factor: 1 gram per cup equals 0.2638675595 pounds per cubic foot. You can also use the swap control in the converter above to flip the direction instantly.
What is a pound per cubic foot?
Pound per Cubic foot (lb/ft3) measures density. The US customary unit for expressing density, commonly used in construction and engineering material specifications. It is classified as a US customary density unit.
What is a gram per cup?
Gram per Cup (g/cup) is a unit of density.
Is the pound per cubic foot to gram per cup conversion exact?
Yes. Both pound per cubic foot and gram per cup are defined by fixed standards rather than physical artifacts, so the factor of 3.789780001 used above is exact to as many digits as you choose to display.
Where is the pound per cubic foot still used today?
United States (construction, engineering, materials specifications)
What's the difference between density and mass concentration?
Density is the mass of a pure substance or material per unit volume. Mass concentration is the mass of one component — like a dissolved solute — within a mixture's total volume. The two use the same kind of units but describe different physical situations.