Mass per volume density.
Grain per Cubic inches to Pounds per Gallon Converter — gr/in3 to lb/gal
Convert Grain per Cubic inch (gr/in3) to Pound per Gallon (lb/gal) using the exact conversion factor (1 grain per cubic inch = 0.033 pound per gallon). See the formula, worked examples, conversion table, and common uses.
Grain 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 3.954272101 / 119.8264273.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Grain per Cubic inches to Pounds per Gallon
Grain 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 = grain per cubic inches × 0.033
This factor comes from each unit's defined relationship to the category's base unit: 1 grain per cubic inch equals 3.95427210146 base units, and 1 pound per gallon equals 119.826427317 base units, so dividing one by the other gives the direct grain per cubic inch-to-pound per gallon factor of 0.033.
Simple example
1 gr/in3 × 0.033 = 0.033 lb/gal
1 grain per cubic inch = 0.033 pounds per gallon.
Real-world example
1,000 gr/in3 × 0.033 = 33 lb/gal
1,000 grain per cubic inches = 33 pounds per gallon.
Conversion table
| Grain per Cubic inch (gr/in3) | Pound per Gallon (lb/gal) |
|---|---|
| 0.1 gr/in3 | 0.0033 lb/gal |
| 1 gr/in3 | 0.033 lb/gal |
| 10 gr/in3 | 0.33 lb/gal |
| 100 gr/in3 | 3.3 lb/gal |
| 1,000 gr/in3 | 33 lb/gal |
| 10,000 gr/in3 | 330 lb/gal |
Reverse conversion: Pound per Gallon to Grain per Cubic inch
0.033 lb/gal × 30.3030303 = 1 gr/in3
0.033 pounds per gallon = 1 grain per cubic inches.
grain per cubic inches = pounds per gallon × 30.303030303
For a page dedicated to this direction, see Pound per Gallon to Grain per Cubic inch.
Understanding the Grain per Cubic inch (gr/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 grain per cubic inch?
1 grain per cubic inch equals 0.033 pounds per gallon, using the exact defined conversion factor rather than an estimate.
How do I convert grain per cubic inch to pound per gallon?
Multiply the grain per cubic inch value by 0.033. The converter above does this instantly to whatever precision you set.
How do I convert pound per gallon back to grain per cubic inch?
Use the reverse factor: 1 pound per gallon equals 30.3030303 grain per cubic inches. You can also use the swap control in the converter above to flip the direction instantly.
What is a grain per cubic inch?
Grain per Cubic inch (gr/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 grain per cubic inch to pound per gallon conversion exact?
Yes. Both grain per cubic inch and pound per gallon are defined by fixed standards rather than physical artifacts, so the factor of 0.033 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.