Fluid Oz to Quarts Converter
32 fl oz × 0.03125 = 1 qt
Divide fluid oz by 32 to get quarts. 32 fl oz = 1 qt, 64 fl oz = 2 qt, and 128 fl oz = 4 qt (1 gallon). The relationship is exact by definition in the US customary system, so there is no rounding to worry about.
One US quart is 0.946352946 L, or 946.35 mL. It also equals 4 US cups and 2 US pints. If you are working with an imperial quart instead, used in the UK and Canada, the number changes: 1 imperial quart = 40 imperial fluid oz = 1.1365 L. The sections below cover the recipe and container situations where the answer actually matters.
How many fluid oz are in a quart?
There are exactly 32 US fluid oz in 1 US quart. That figure is a definition, not a measurement, so it never needs rounding. Half a quart is 16 fl oz (1 US pint), and a quarter of a quart is 8 fl oz (1 US cup).
The chain upward is just as clean: 2 quarts = 64 fl oz, 4 quarts = 128 fl oz, and 4 quarts is also 1 US gallon. That is why a gallon of milk contains 128 fl oz (3.79 L) and why a quart carton of stock is labelled 32 oz. If you are ever unsure which way to move, remember that quarts are the larger unit, so the oz number is always the bigger one.
The imperial quart is a separate unit. It holds 40 imperial fluid oz and measures 1.1365 L, making it about 20% larger than the US quart. British and Canadian recipes that predate metrication may use it, so check the origin of a recipe before assuming 32.
The formula
quarts = fluid oz ÷ 32. To go the other way, multiply quarts by 32. Because 32 is a power of two, you can often do it in your head by halving: 32 fl oz is 1 qt, so 16 fl oz is half a quart, 8 fl oz is a quarter, and 4 fl oz is an eighth. Anything that is not a neat multiple lands on a decimal, 20 fl oz is 0.625 qt (591 mL), for example.
- Take your figure in US fluid oz, for example, 48 fl oz.
- Divide by 32, because 1 US quart contains exactly 32 US fluid oz.
- Read the result: 48 ÷ 32 = 1.5, so 48 fl oz = 1.5 qt (1 quart plus 1 pint).
What is a fluid oz?
A US fluid oz is a unit of volume equal to 29.5735 mL. It measures how much space a liquid occupies, which is why it appears on drink cans, bottles and stock cartons. It is not the same unit as the oz used for weight (1 oz = 28.3495 g), and the two are not interchangeable, 8 fl oz of honey and 8 oz of honey are different quantities.
The imperial fluid oz, still seen in the UK, is slightly smaller at 28.4131 mL. The difference is small enough to ignore for a single oz and large enough to matter across a quart: 32 US fl oz is 946 mL, while 32 imperial fl oz is 909 mL.
What is a quart?
A quart is a US customary unit of volume equal to 32 fluid oz, 4 cups, 2 pints, or a quarter of a gallon, the name comes from that quarter. In litres it is 0.946352946 L, so a US quart is about 5.7% smaller than a litre. That near-miss is the source of most quart confusion: a quart carton and a 1 L carton sit side by side on the shelf and look identical.
Quarts survive mainly in three places: liquid groceries (stock, broth, milk, ice cream), cookware capacity (stockpots, Dutch ovens, slow cookers), and home canning. Outside the United States the quart has largely been replaced by the litre, and even in the US most packaging now prints both figures.
Quarts in the kitchen: cartons, pots and cooker sizes
The two numbers worth memorising are 1 qt = 32 fl oz = 4 cups and 2 qt = 64 fl oz = 8 cups. Almost every quart question in a kitchen resolves to one of those. A carton of stock or broth labelled 32 oz is exactly 1 quart, so a recipe calling for a quart of chicken stock means one carton, no measuring required. Two cartons give you the 2 qt (64 fl oz) that most braises and risottos ask for.
Past about 8 cups, stop thinking in cups and start thinking in quarts. Nobody measures 25 cups of water for a stockpot; they fill it to 6 quarts. Cookware is sized the same way, and the capacity on the box is the total volume, not the usable one. A 6-quart slow cooker holds 5.7 L (192 fl oz) filled to the brim, and manufacturers generally want it between half and two-thirds full, which puts the working range at roughly 3 to 4 qt (96–128 fl oz). A 5-quart Dutch oven is 4.7 L (160 fl oz). Canning jars follow the same scale: a quart jar takes 32 fl oz of product.
The one place the quart-litre near-miss bites is scaling. A quart is 0.946 L, so a recipe built around a 1 L carton and executed with a 1 qt carton comes out 5.7% short on liquid. In a soup or a braise that difference disappears into evaporation and nobody notices. In a brine, a custard, a pickling liquid or anything where the ratio of salt, sugar or egg to liquid sets the outcome, 5.7% is enough to change the result. When the ratio matters, convert properly: 1 qt = 946.35 mL, not 1000 mL.
Fluid oz to quarts conversion table
All values use the US fluid oz and the US liquid quart, where 32 fl oz = 1 qt exactly. Imperial quarts hold 40 imperial fluid oz.
| Fluid oz (US) | Quarts (US) |
|---|---|
| 1 | 32 |
| 2 | 64 |
1 fl oz = 0.03125 qt
Popular quart conversions
Frequently asked questions
There are exactly 32 US fluid oz in 1 US quart. The figure is exact by definition, so 2 qt = 64 fl oz and 4 qt = 128 fl oz. An imperial quart holds 40 imperial fluid oz instead.
There are 4 US cups in 1 US quart, because 1 cup is 8 fl oz and 4 × 8 = 32 fl oz. So 2 qt = 8 cups and half a quart = 2 cups (16 fl oz).
No. 1 US quart = 0.946352946 L, which is about 5.7% smaller than a litre. A 1 L carton holds roughly 33.8 fl oz, while a quart carton holds 32 fl oz. They look interchangeable on a shelf but are not identical.
There are 4 US quarts in 1 US gallon. That works out to 128 fl oz (3.79 L). The word quart is short for quarter, a quarter of a gallon.
A quart of stock is 32 fl oz (946 mL), which is exactly one standard carton. Recipes that call for a quart of stock mean one carton; a recipe calling for 64 fl oz needs two.
64 fl oz is 2 quarts. That is also 8 cups, 4 pints, or 1.89 L. It is half a gallon.
A 6-quart cooker. Manufacturers recommend filling between half and two-thirds, so a 6 qt (5.7 L) cooker has a working capacity of roughly 3 to 4 qt (96–128 fl oz). Filling a 4-quart cooker to 4 quarts leaves no headroom.
16 fl oz is 0.5 quarts. That is 1 US pint, 2 cups, or 473 mL.
An imperial quart holds 40 imperial fluid oz, which is 1.1365 L. It is about 20% larger than the US quart's 32 US fl oz (0.946 L), so UK and older Canadian recipes need the imperial figure.
128 fl oz is 4 quarts, which is exactly 1 US gallon (3.79 L). It is also 16 cups or 8 pints.