ounces per US gallon (oz/gal) to pounds per US gallon (lb/gal) conversion

What is the Ounce per US Gallon?

The ounce per US gallon is a unit of density expressing the mass in avoirdupois ounces contained in one US liquid gallon. It appears in everyday US contexts such as mixing ratios, water treatment, and beverage or fuel formulations.

Definition

One ounce per US gallon equals the mass of one avoirdupois ounce (28.349523125 g) divided by the volume of one US liquid gallon (3.785411784 L).

$$1\ \text{oz/gal} = 7.48915\ \text{kg/m}^3$$

Here the ounce is the avoirdupois ounce of mass and the gallon is the US liquid gallon (exactly 3.785411784 L, or 231 cubic inches). Using the imperial gallon (4.54609 L) instead gives a different value of about 6.236 kg/m³, so the gallon variant must always be specified.

Origin and History

The US gallon descends from the English wine gallon of 231 cubic inches, retained by the United States after Britain adopted the larger imperial gallon in 1824. Pairing it with the avoirdupois ounce created a practical density and dosing unit for American trade and agriculture.

Law and Notable Facts

This is a derived unit fixed by the exact definitions of the avoirdupois ounce and the US liquid gallon. It is especially common in dosing and concentration work, where an "ounces per gallon" rate is easy to measure and mix by hand.

Real-World Examples and Conversions

• Water (about 1000 kg/m³) corresponds to roughly 133.5 oz/gal.
• A concentration of 1 oz/gal is about 7.489 kg/m³, or 7.489 g/L.
• 8 oz/gal (a half pound per gallon) equals about 59.9 kg/m³.
• 16 oz/gal (one pound per gallon) equals about 119.8 kg/m³.

What is the Pound per US Gallon?

The pound per US gallon is a US customary unit of mass density, giving the number of avoirdupois pounds contained in one US liquid gallon. It is widely used for fuels, paints, chemicals, and other liquids sold by the gallon in the United States.

Definition

One pound per US gallon equals one avoirdupois pound (0.45359237 kg) in one US liquid gallon (231 cubic inches, or 3.785411784×10⁻³ m³). The result is:

$$1\ \text{lb/gal} = 119.826\ \text{kg/m}^3$$

This uses the US gallon; the imperial (UK) gallon is larger (4.54609 L), so 1 lb per imperial gallon equals about 99.776 kg/m³. Values here refer specifically to the US gallon.

Origin and History

The US gallon descends from the English wine gallon of 231 cubic inches, retained by the United States after Britain redefined its gallon in 1824. Combined with the avoirdupois pound, pounds per US gallon became the standard density and shipping-weight measure for American liquid commerce.

Law and Notable Facts

The US gallon is defined as exactly 231 cubic inches and the pound as exactly 0.45359237 kg, making the conversion exact. A key fact: water weighs about 8.34 lb/gal, the basis of the water-treatment industry's "pounds per million gallons" dosing calculations.

Real-World Examples and Conversions

Water is about 8.34 lb/gal, gasoline roughly 6.0–6.3 lb/gal, and diesel about 7.1 lb/gal. Milk is around 8.6 lb/gal. To convert to kilograms per cubic meter, multiply by 119.826; to kilograms per liter, multiply by 0.119826.