Mass per volume density.
Grains per Fluid ounce to Grains per Gallon Converter — gr/fl oz to gr/gal
Convert Grain per Fluid ounce (gr/fl oz) to Grain per Gallon (gr/gal) using the exact conversion factor (1 grain per fluid ounce = 128 grain per gallon). See the formula, worked examples, and conversion table.
Grains per Fluid ounce to Grains 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 2.191111814 / 0.01711806105.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Grains per Fluid ounce to Grains per Gallon
Grain per Fluid ounce and Grain 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
grains per gallon = grains per fluid ounce × 128
This factor comes from each unit's defined relationship to the category's base unit: 1 grain per fluid ounce equals 2.19111181379 base units, and 1 grain per gallon equals 0.0171180610453 base units, so dividing one by the other gives the direct grain per fluid ounce-to-grain per gallon factor of 128.
Simple example
1 gr/fl oz × 128 = 128 gr/gal
1 grain per fluid ounce = 128 grains per gallon.
Real-world example
1,000 gr/fl oz × 128 = 128,000 gr/gal
1,000 grains per fluid ounce = 128,000 grains per gallon.
Conversion table
| Grain per Fluid ounce (gr/fl oz) | Grain per Gallon (gr/gal) |
|---|---|
| 0.1 gr/fl oz | 12.8 gr/gal |
| 1 gr/fl oz | 128 gr/gal |
| 10 gr/fl oz | 1,280 gr/gal |
| 100 gr/fl oz | 12,800 gr/gal |
| 1,000 gr/fl oz | 128,000 gr/gal |
| 10,000 gr/fl oz | 1,280,000 gr/gal |
Reverse conversion: Grain per Gallon to Grain per Fluid ounce
128 gr/gal × 0.0078125 = 1 gr/fl oz
128 grains per gallon = 1 grain per fluid ounce.
grains per fluid ounce = grains per gallon × 0.0078125
For a page dedicated to this direction, see Grain per Gallon to Grain per Fluid ounce.
Understanding the Grain per Fluid ounce (gr/fl oz)
Mass per volume density.
Understanding the Grain per Gallon (gr/gal)
Mass per volume density.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many grains per gallon are in 1 grain per fluid ounce?
1 grain per fluid ounce equals 128 grains per gallon, using the exact defined conversion factor rather than an estimate.
How do I convert grain per fluid ounce to grain per gallon?
Multiply the grain per fluid ounce value by 128. The converter above does this instantly to whatever precision you set.
How do I convert grain per gallon back to grain per fluid ounce?
Use the reverse factor: 1 grain per gallon equals 0.0078125 grains per fluid ounce. You can also use the swap control in the converter above to flip the direction instantly.
What is a grain per fluid ounce?
Grain per Fluid ounce (gr/fl oz) is a unit of density.
What is a grain per gallon?
Grain per Gallon (gr/gal) is a unit of density.
Is the grain per fluid ounce to grain per gallon conversion exact?
Yes. Both grain per fluid ounce and grain per gallon are defined by fixed standards rather than physical artifacts, so the factor of 128 used above is exact to as many digits as you choose to display.
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.