Quarts in a Gallon: Gallons, Quarts, Pints and Cups Converter

This converter answers how many quarts in a gallon, and every question like it, for US liquid measure. Pick the unit you have and the unit you want from gallons, quarts, pints, cups, fluid ounces and litres. The headline gives the answer in your chosen unit, and the cards show the same volume in all six at once.

The US system halves at every step. A gallon is 4 quarts, a quart is 2 pints, a pint is 2 cups and a cup is 8 fluid ounces. Those ratios are written into NIST Handbook 44, which defines the US gallon as exactly 231 cubic inches and each smaller unit as a fixed fraction of it. Because the inch is exactly 2.54 cm, the gallon is also an exact number of litres: 3.785411784. The converter uses that exact figure, so litre answers are rounded only for display.

Liquid measure on this page is US customary. British gallons, quarts and pints are larger and are not used.

1. Type the amount. Fractions go in as decimals, so half a pint is 0.5 and one and a half quarts is 1.5.
2. Choose the unit you have under From and the unit you want under To.
3. Read the headline, then the cards, which list gallons, quarts, pints, cups, fluid ounces and litres together.

The presets load 4 quarts to cups, 8 cups to quarts and 45 litres to gallons. Below the converter, a table lists common amounts across all the customary units, and a second table turns litres into US gallons and quarts. Both download as CSV.

1. Read the units. The From and To choices select two units from the list. A negative amount is read as zero.

1. Convert through the cubic metre. Each unit is stored once as its exact size in cubic metres, built from the gallon of 231 cubic inches: the quart is a quarter of the gallon, the pint an eighth, the cup a sixteenth and the fluid ounce a 128th. The litre is a thousandth of a cubic metre. The converter multiplies your amount by the size of the From unit and divides by the size of the To unit.

For gallons to quarts, that ratio is the gallon over a quarter gallon, exactly 4.

1. Fill in every unit. The same conversion runs once for each of the six units, which is what the cards show.

1. Round for display only. The arithmetic runs at 34 significant digits. Customary units are shown to six decimal places and litres to four, rounded half up with trailing zeros dropped. For whole-number amounts, every customary answer is exact except fluid ounces turned into gallons, where an eighth of a sixteenth needs seven places.

The default is 1 gallon to quarts:

1. Quarts: 1 × 4 = 4 quarts.
2. The cards: 8 pints, 16 cups, 128 fluid ounces and 3.7854 litres.

4 quarts to cups: 4 × 4 = 16 cups, which is back to one gallon.

8 cups to quarts: 8 ÷ 4 = 2 quarts, which is half a gallon or 64 fluid ounces.

5 cups to quarts: 5 ÷ 4 = 1.25 quarts, or 2.5 pints.

45 litres to gallons: 45 ÷ 3.785411784 = 11.887742 gallons, or 47.550969 quarts.

Each row is from the converter's reference table, which also covers a quarter gallon, 3 quarts, 1.5 pints and more cup amounts.

Four. A quart is named for being a quarter of a gallon, and the US definitions keep that exactly: 4 quarts to the gallon, so 2 quarts is half a gallon. A quart is in turn 2 pints or 4 cups, which is why a gallon holds 16 cups.

If a recipe or a container asks for a "quarter", it almost always means a quart. Four quarts of stock is one gallon; one quart is 4 cups.

Fuel, aquariums and drink bottles often mix gallons and litres. One US gallon is exactly 3.785411784 litres, which the converter shows as 3.7854. The second reference table runs the other way: 1 litre is 0.264172 US gallons, 20 litres is 5.283441 gallons and 100 litres is 26.417205 gallons.

• Imperial measures. A British gallon, quart and pint are each bigger than the US ones. The British pint, for example, is 0.56826125 litres by the Weights and Measures Act 1985. Use a UK converter for those.
• US dry measure. The US also has a dry pint and dry quart for things like berries, defined from the bushel rather than the gallon. They are a little larger than the liquid units and are not used here.
• Weight. A gallon of water and a gallon of honey take up the same space but weigh very different amounts. The water weight calculator on this site gives the weight of a volume of water.
• Fractions typed as fractions. The box takes decimals. A third of a cup has no exact decimal.

• Assuming metric halves. Customary units go in twos and fours, not tens. Half a gallon is 2 quarts, not 5.
• Mixing up pints and quarts. A pint is 2 cups; a quart is 4. A recipe that halves a quart wants a pint.
• Using a UK pint in a US recipe. The British pint is larger, so a British recipe's pints and a US recipe's pints are not interchangeable.
• Rounding litres early. Converting 3.8 litres per gallon instead of 3.785411784 adds up over a big tank.

• NIST Handbook 44, Appendix C, General Tables of Units of Measurement: the US gallon, quart, pint, cup and fluid ounce. nist.gov/pml/owm/nist-handbook-44-current-edition
• NIST Special Publication 811, Guide for the Use of the International System of Units (2008), Appendix B: conversion factors to SI. nist.gov/pml/special-publication-811
• UK legislation, Weights and Measures Act 1985, Schedule 1: the imperial pint. legislation.gov.uk/ukpga/1985/72/schedule/1