Fluid Ounces to Liters (oz to L)

Common questions

How many litres is a fluid ounce?

There are two answers, because there are two fluid ounces. An imperial fluid ounce, the one this page opens on, is exactly 0.0284130625 litres, which is 28.4130625 mL. A US fluid ounce is exactly 0.0295735295625 litres, which is 29.5735295625 mL. The imperial ounce is the smaller of the two by about 4%, so using the wrong one on 32 oz is the difference between 0.909218 L and 0.946352946 L. Both figures are definitions rather than measurements, which is why the converter prints every digit of them instead of rounding to three.

How do I switch this page to US fluid ounces?

Open the menu labelled From, under the number you type, and choose Fluid ounce (US). The To box stays on Litre and the answer changes the moment you pick it. Both ounces carry the symbol fl oz here, so choose by the name in brackets: Fluid ounce (imperial) is the British ounce and Fluid ounce (US) is the American one. This page always opens on the imperial ounce, even if the US ounce was the last pair you used in the main converter, because that specific conversion is the page's job.

What are 8, 16 and 32 fluid ounces in litres?

In imperial fluid ounces: 8 oz is 0.2273045 L, 16 oz is 0.454609 L, 20 oz is 0.56826125 L, which is a British pint, and 32 oz is 0.909218 L. The same counts in US fluid ounces read 0.2365882365 L, 0.473176473 L, 0.59147059125 L and 0.946352946 L. Every one of those is exact, because multiplying a whole number of ounces by either factor gives a decimal that stops. Typing 33.8 with Fluid ounce (US) selected gives 0.999585299212 L, which is where the rule of thumb that a litre is 33.8 oz comes from. The Copy result button copies the headline exactly as printed, without the thousands separators.

Is a fluid ounce the same as an ounce of weight?

No. A fluid ounce measures volume and an ounce of weight, the avoirdupois ounce, measures mass: exactly 0.028349523125 kg, which this converter handles under its Mass category rather than on this page. The names overlap because the imperial fluid ounce was set as the space one ounce of water occupies, so for water the two nearly meet: 28.4130625 mL of water weighs a little over 28 grams. For oil, flour or honey they do not meet, and no unit converter can bridge them without knowing the density, which is what the grams to cups tool asks for.

How do I convert litres back to fluid ounces?

Press the button between the two boxes, labelled Swap units, and the page converts litres into whichever fluid ounce is selected. One litre is 35.1950797279 imperial fluid ounces or 33.8140227018 US fluid ounces, half a litre is 17.5975398639 or 16.9070113509, and two litres is 70.3901594557 or 67.6280454037. Neither division gives a short decimal, so the converter shows twelve significant digits and you round where your job needs it.

Which fluid ounce does my bottle or recipe mean?

A US recipe, a US nutrition label and a bottle sized in the United States mean the US fluid ounce. A British recipe, a pub measure and older imperial cookbooks mean the imperial one. Pint sizes are the quickest check: a British pint is 20 imperial fluid ounces, 0.56826125 L, while a US pint is 16 US fluid ounces, 0.473176473 L. If the label already carries a metric figure, use that and skip the conversion: a 500 mL bottle is 17.5975398639 imperial fluid ounces or 16.9070113509 US ones.

Where are the imperial pint and gallon in the list underneath?

Behind the switch marked Show 5 more, in the row under the converter. By default the list below the answer holds the common volume units: millilitres, litres, cubic metres, teaspoons, tablespoons, US fluid ounces, cups, pints, quarts and gallons. Turning that switch on adds the imperial pint, the imperial gallon, cubic inches and cubic feet. The imperial fluid ounce itself never appears in the list on this page, because the list leaves out the unit you are converting from.

Does anything I type leave my browser?

No. The conversion is a multiplication and a division against a table of factors that ships with the page, so there is no upload and no account, and once the page has loaded the arithmetic needs no network. The amount you typed is kept in your own browser's storage so the field is where you left it next time, and the Start over button at the top of the page clears it. Opening this page does not change the pair the main converter remembers: that stays on whatever you last chose there.