A gallon in liquid is equal to approximately 128 fluid ounces.

What’s an ounce? An ounce is a measurement that systematizes the weight of a volume of liquid or solids, typically on a scale.

This measurement is created according to the avoirdupois system and means approximately 0.0353 pounds, which are often used for substances such as milk and water.

One tablespoonful equals one ounce of water if it falls from 8 inches high onto a surface that has been measured with precision to be level and horizontal with no obstacle present except gravity.

An American quart (liquid) contains 32 US fluid ounces; two quarts make up one U.S liquid gallon (128 ounces).

A gallon is equivalent to 128 ounces, or 3.78 liters.

A quart is 16 ounces and a pint is 32 ounces. The value of 128 was derived by combining these two values, 4 quarts equals just over half a gallon (1/2gal = 64oz).

People then started counting out pints to measure liquids in other containers like buckets or barrels and then eventually rulers were made with markings for the measurements they would be most likely to use – one inch equalled 2 feet so that wineskins could have an accurate measurement when gauging the height of wine barrels, but also so that wine merchants could know how tall their wares were as compared to other buildings on the street.

There are 128 fluid ounces in a gallon.

This unit of volumetric measurement is equivalent to 1/8th of what’s called a wine cask, which back when these were used by the English royal family would hold about 266 gallons of wine.

If you’re looking for liquid measurement for the US’ usage though then there are 161.7825 cubic inches per gallon (approximately).

How does that work out? Well, if you overlook milliliters and just consider centimeters then a gallon has 3785.5185 cm3 volume-wise so I’ll let your math skills do the rest….

Some other units of measure include barrells and hogsheads both measuring 2 barrels or 6 hogs.