Pound per cubic foot to Pound per US gallon Conversion Table
| Pound per cubic foot (lb/ft3) | Pound per US gallon (lb/gal) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 0.0765 lb/ft³ | 0.0102 lb/gal | Dry atmospheric air at standard temperature and pressure | 0.0765 × 0.13368 = 0.0102 lb/gal |
| 7.491 lb/ft³ | 1.001 lb/gal | Aviation balsa wood lightweight core material | 7.491 × 0.13368 = 1.001 lb/gal |
| 14.983 lb/ft³ | 2.003 lb/gal | Natural cork stopper insulation material | 14.983 × 0.13368 = 2.003 lb/gal |
| 33.337 lb/ft³ | 4.457 lb/gal | Elemental metallic lithium solid | 33.337 × 0.13368 = 4.457 lb/gal |
| 42.451 lb/ft³ | 5.675 lb/gal | Automotive gasoline motor fuel blend | 42.451 × 0.13368 = 5.675 lb/gal |
| 49.942 lb/ft³ | 6.676 lb/gal | Industrial denatured ethyl alcohol | 49.942 × 0.13368 = 6.676 lb/gal |
| 57.246 lb/ft³ | 7.653 lb/gal | Freshwater ice crystal density at 0°C | 57.246 × 0.13368 = 7.653 lb/gal |
| 62.303 lb/ft³ | 8.329 lb/gal | Liquid water density at ambient 20°C | 62.303 × 0.13368 = 8.329 lb/gal |
| 62.428 lb/ft³ | 8.345 lb/gal | Pure liquid water density baseline at 4°C | 62.428 × 0.13368 = 8.345 lb/gal |
| 78.659 lb/ft³ | 10.515 lb/gal | Pharmaceutical grade vegetable glycerin | 78.659 × 0.13368 = 10.515 lb/gal |
| 149.827 lb/ft³ | 20.029 lb/gal | Standard reinforced structural building concrete | 149.827 × 0.13368 = 20.029 lb/gal |
| 168.556 lb/ft³ | 22.533 lb/gal | Commercial aerospace aluminum alloy 6061 | 168.556 × 0.13368 = 22.533 lb/gal |
| 490.06 lb/ft³ | 65.512 lb/gal | Structural carbon construction steel | 490.06 × 0.13368 = 65.512 lb/gal |
| 559.355 lb/ft³ | 74.775 lb/gal | Pure electrical grade copper cathode | 559.355 × 0.13368 = 74.775 lb/gal |
| 707.933 lb/ft³ | 94.637 lb/gal | Refined elemental lead radiation shield | 707.933 × 0.13368 = 94.637 lb/gal |
| 1,206.108 lb/ft³ | 161.233 lb/gal | Refined 24-karat monetary bullion gold | 1,206.108 × 0.13368 = 161.233 lb/gal |
Pound per cubic foot to Pound per US gallon Formula & Unit Definitions
The exact ratio derives directly from the geometry of US customary volumetric measures: 1 cubic foot equals 12³ = 1,728 cubic inches, while 1 US liquid gallon is legally defined as exactly 231 cubic inches. Therefore, 1 gallon occupies exactly 231 / 1,728 = 77 / 576 ≈ 0.133680556 cubic feet. Because both units share the same mass unit (the pound), 1 lb/ft³ equals 231 / 1,728 ≈ 0.13368056 lb/gal. Multiplying any density in lb/ft³ by 0.13368056 yields its value in lb/gal.
Quick Estimation: To estimate lb/ft³ to lb/gal mentally, divide by 7.5 (or divide by 15 and double). For example, water at 62.4 lb/ft³ divided by 7.5 gives approximately 8.32 lb/gal.
Pound per cubic foot (lb/ft3)
Source Unit- Standard American engineering unit for building materials, soils, HVAC airflow, and timber.
- Measures the gravitational force or mass contained within a 1 cubic foot cube (1,728 in³).
- Baseline anchor where water equals ~62.4 lb/ft³ and normal structural concrete is ~145-150 lb/ft³.
Pounds per US Gallon (lb/gal)
Target Unit- Standard American industrial process unit for liquid chemicals, paints, resins, and fuels.
- Measures the mass contained in 1 US liquid gallon (defined legally as exactly 231 in³).
- Baseline anchor where liquid water equals ~8.345 lb/gal and diesel fuel is ~7.01 lb/gal.
Frequently Asked Questions
Q.What is the exact formula for lb/ft³ to lb/gal?
Density (lb/gal) = Density (lb/ft³) × (231 / 1,728) ≈ Density (lb/ft³) × 0.13368056. For reverse conversion from lb/gal to lb/ft³, multiply by 7.4805195.
Q.What is the physical difference between Pound per cubic foot and Pound per US gallon?
Pound per cubic foot measures density in a 1-foot cube (1,728 in³) used for structural building materials, while Pound per US gallon measures density in a standard 231-cubic-inch container used for commercial fluids.
Q.How many gallons are in one cubic foot?
There are exactly 1,728 / 231 = 77 / 576 ≈ 7.480519 US liquid gallons in one cubic foot.