Mass per volume density.
Gram per Cubic inches to Pounds per Gallon Converter — g/in3 to lb/gal
Convert Gram per Cubic inch (g/in3) to Pound per Gallon (lb/gal) using the exact conversion factor (1 gram per cubic inch = 0.5092678256 pound per gallon). See the formula, worked examples, conversion table, and common uses.
Gram per Cubic inches to Pounds per Gallon 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 61.02374409 / 119.8264273.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Gram per Cubic inches to Pounds per Gallon
Gram per Cubic inch and Pound per Gallon 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. Both are mass per volume density units.
Formula
pounds per gallon = gram per cubic inches × 0.509267825647
This factor comes from each unit's defined relationship to the category's base unit: 1 gram per cubic inch equals 61.0237440947 base units, and 1 pound per gallon equals 119.826427317 base units, so dividing one by the other gives the direct gram per cubic inch-to-pound per gallon factor of 0.509267825647.
Simple example
1 g/in3 × 0.5092678256 = 0.5092678256 lb/gal
1 gram per cubic inch = 0.5092678256 pounds per gallon.
Real-world example
1,000 g/in3 × 0.5092678256 = 509.2678256 lb/gal
1,000 gram per cubic inches = 509.2678256 pounds per gallon.
Conversion table
| Gram per Cubic inch (g/in3) | Pound per Gallon (lb/gal) |
|---|---|
| 0.1 g/in3 | 0.0509267826 lb/gal |
| 1 g/in3 | 0.5092678256 lb/gal |
| 10 g/in3 | 5.092678256 lb/gal |
| 100 g/in3 | 50.92678256 lb/gal |
| 1,000 g/in3 | 509.2678256 lb/gal |
| 10,000 g/in3 | 5,092.678256 lb/gal |
Reverse conversion: Pound per Gallon to Gram per Cubic inch
0.5092678256 lb/gal × 1.963603333 = 0.9999999999 g/in3
0.5092678256 pounds per gallon = 0.9999999999 gram per cubic inches.
gram per cubic inches = pounds per gallon × 1.96360333333
For a page dedicated to this direction, see Pound per Gallon to Gram per Cubic inch.
Understanding the Gram per Cubic inch (g/in3)
Mass per volume density.
Understanding the Pound per Gallon
Pound per Gallon (lb/gal) measures density. The US customary unit for liquid density, based on the US gallon (231 cubic inches). It is classified as a US customary density unit.
Where it's used: United States (paint, fuel, and industrial liquid density specifications)
lb/gal vs. lb/ft³. Both are US customary density units; they're related through the real, fixed relationship between the US gallon and the cubic foot (1 cubic foot ≈ 7.48 US gallons), not a round conversion factor.
Uses of the Pound per Gallon today
- US paint and coatings density specifications
- US fuel and petroleum liquid density specs
- Industrial liquid handling and shipping weight calculations
Pound per Gallon — 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 pounds per gallon are in 1 gram per cubic inch?
1 gram per cubic inch equals 0.5092678256 pounds per gallon, using the exact defined conversion factor rather than an estimate.
How do I convert gram per cubic inch to pound per gallon?
Multiply the gram per cubic inch value by 0.5092678256. The converter above does this instantly to whatever precision you set.
How do I convert pound per gallon back to gram per cubic inch?
Use the reverse factor: 1 pound per gallon equals 1.963603333 gram per cubic inches. You can also use the swap control in the converter above to flip the direction instantly.
What is a gram per cubic inch?
Gram per Cubic inch (g/in3) is a unit of density.
What is a pound per gallon?
Pound per Gallon (lb/gal) measures density. The US customary unit for liquid density, based on the US gallon (231 cubic inches). It is classified as a US customary density unit.
Is the gram per cubic inch to pound per gallon conversion exact?
Yes. Both gram per cubic inch and pound per gallon are defined by fixed standards rather than physical artifacts, so the factor of 0.5092678256 used above is exact to as many digits as you choose to display.
What is the difference between lb/gal vs. lb/ft³?
Both are US customary density units; they're related through the real, fixed relationship between the US gallon and the cubic foot (1 cubic foot ≈ 7.48 US gallons), not a round conversion factor.