Pound per US gallon to Pound per cubic foot Conversion Table
| Pound per US gallon (lb/gal) | Pound per cubic foot (lb/ft3) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 0.0102 lb/gal | 0.0765 lb/ft³ | Dry atmospheric air at standard temperature and pressure | 0.0102 × 7.4805 = 0.0765 lb/ft³ |
| 1.001 lb/gal | 7.491 lb/ft³ | Aviation balsa wood lightweight core material | 1.001 × 7.4805 = 7.491 lb/ft³ |
| 2.003 lb/gal | 14.983 lb/ft³ | Natural cork stopper insulation material | 2.003 × 7.4805 = 14.983 lb/ft³ |
| 4.457 lb/gal | 33.337 lb/ft³ | Elemental metallic lithium solid | 4.457 × 7.4805 = 33.337 lb/ft³ |
| 5.675 lb/gal | 42.451 lb/ft³ | Automotive gasoline motor fuel blend | 5.675 × 7.4805 = 42.451 lb/ft³ |
| 6.676 lb/gal | 49.942 lb/ft³ | Industrial denatured ethyl alcohol | 6.676 × 7.4805 = 49.942 lb/ft³ |
| 7.653 lb/gal | 57.246 lb/ft³ | Freshwater ice crystal density at 0°C | 7.653 × 7.4805 = 57.246 lb/ft³ |
| 8.329 lb/gal | 62.303 lb/ft³ | Liquid water density at ambient 20°C | 8.329 × 7.4805 = 62.303 lb/ft³ |
| 8.345 lb/gal | 62.428 lb/ft³ | Pure liquid water density baseline at 4°C | 8.345 × 7.4805 = 62.428 lb/ft³ |
| 10.515 lb/gal | 78.659 lb/ft³ | Pharmaceutical grade vegetable glycerin | 10.515 × 7.4805 = 78.659 lb/ft³ |
| 20.029 lb/gal | 149.827 lb/ft³ | Standard reinforced structural building concrete | 20.029 × 7.4805 = 149.827 lb/ft³ |
| 22.533 lb/gal | 168.556 lb/ft³ | Commercial aerospace aluminum alloy 6061 | 22.533 × 7.4805 = 168.556 lb/ft³ |
| 65.512 lb/gal | 490.06 lb/ft³ | Structural carbon construction steel | 65.512 × 7.4805 = 490.06 lb/ft³ |
| 74.775 lb/gal | 559.355 lb/ft³ | Pure electrical grade copper cathode | 74.775 × 7.4805 = 559.355 lb/ft³ |
| 94.637 lb/gal | 707.933 lb/ft³ | Refined elemental lead radiation shield | 94.637 × 7.4805 = 707.933 lb/ft³ |
| 161.233 lb/gal | 1,206.108 lb/ft³ | Refined 24-karat monetary bullion gold | 161.233 × 7.4805 = 1,206.108 lb/ft³ |
Pound per US gallon to Pound per cubic foot Formula & Unit Definitions
The exact ratio originates from the geometry of US customary volumetric measures: 1 cubic foot equals 1,728 cubic inches, while 1 US liquid gallon equals exactly 231 cubic inches. Therefore, 1 cubic foot holds exactly 1,728 / 231 = 576 / 77 ≈ 7.4805195 US gallons. Since both measures share the same unit of mass (the pound), 1 lb/gal equals 1,728 / 231 ≈ 7.4805195 lb/ft³. Multiplying any density in lb/gal by 7.4805195 converts it directly to lb/ft³.
Quick Estimation: To estimate lb/gal to lb/ft³ mentally, multiply by 7.5 (or multiply by 15 and divide by 2). For example, a heavy paint at 10.0 lb/gal multiplied by 7.5 gives approximately 75 lb/ft³.
Pound per US gallon (lb/gal)
Source Unit- Standard American industrial measure for paints, coatings, petrochemicals, and liquid adhesives.
- Represents the gravitational mass contained within a 231-cubic-inch US liquid gallon.
- Baseline anchor where liquid water equals ~8.345 lb/gal and gasoline equals ~5.675 lb/gal.
Pounds per Cubic Foot (lb/ft³)
Target Unit- Standard American engineering unit for building materials, soils, foundation design, and HVAC.
- Measures the gravitational force or mass contained within a 1 cubic foot volume envelope (1,728 in³).
- Baseline anchor where water equals ~62.428 lb/ft³ and reinforced concrete is ~145-150 lb/ft³.
Frequently Asked Questions
Q.What is the exact formula for lb/gal to lb/ft³?
Density (lb/ft³) = Density (lb/gal) × (1,728 / 231) ≈ Density (lb/gal) × 7.4805195. For reverse conversion from lb/ft³ to lb/gal, multiply by 0.13368056.
Q.What is the physical difference between Pound per US gallon and Pound per cubic foot?
Pound per US gallon measures density within a standard 231-cubic-inch container used for commercial liquids, while Pound per cubic foot measures density in a 1,728-cubic-inch space used in structural building design.
Q.Why do you multiply by 7.4805 to get cubic foot density?
Because one cubic foot (1,728 in³) holds exactly 7.48052 US liquid gallons (231 in³). Therefore, whatever one gallon weighs, a full cubic foot holds 7.48052 times that weight.