Imperial Fluid Ounces to Liters (fl oz (UK) to L)

1 imperial fluid ounce equals 0.0284130625 liters exactly.

1 imperial fluid ounce = 0.0284130625 liters

How to convert imperial fluid ounces to liters

To convert imperial fluid ounces to liters, multiply the number of imperial fluid ounces by 0.0284130625. This factor is exact. To go the other way, multiply liters by 35.19507973 (rounded).

liters = imperial fluid ounces × 0.0284130625

Example: 10 imperial fluid ounces = 0.284130625 liters.

Pints, quarts, gallons and fluid ounces differ between the US and the UK. Units are labeled 'US' or 'imperial' to avoid confusion.

About these units

Imperial Fluid Ounce (fl oz (UK))

Imperial (British)Current unit

Exactly 28.4130625 mL. About 4% smaller than the US fluid ounce.

Imperial fluid ounce comes from the 1824 reform that defined the British gallon as the volume of ten pounds of water. Because a gallon was set at 160 fluid ounces, an ounce of water weighs about one ounce of mass, around 28.35 grams. That neat link between volume and weight was the point of the imperial scheme, and it explains why people long thought of fluid ounces and weight ounces as nearly the same.

Today an imperial fluid ounce is exactly 28.4130625 milliliters, one twentieth of an imperial pint. That is about 4 percent smaller than the US fluid ounce at 29.57 mL, so a US recipe using fluid ounces does not map one-for-one onto a British one. UK trade rules restricted its use in 1995, and it lives on mostly on older labels, in bars and in recipes. Twenty of them fill an imperial pint, which makes the pint the easiest way to picture one.

1 imperial fluid ounce = 0.0284130625 liters (exactly).

Sources: Wikipedia: Fluid ounce; UK Weights and Measures Act 1985, Schedule 1

Liter (L)

Metric (SI)Current unit

One cubic decimeter (1,000 cm³). The everyday metric unit of volume for drinks, fuel and cooking.

The liter was born in revolutionary France. In 1795 it was introduced as a republican unit and defined as one cubic decimeter, while the gram was tied to a cubic centimeter of water. The name comes from the older French litron, itself descended from a Byzantine Greek unit of weight, not volume. A small revision of the decimeter in 1798 left the first liter about 1.000974 of today's cubic decimeter, and in 1879 the international metric authorities adopted the liter with the symbol l.

The liter then took a strange detour. In 1901 it was redefined as the space taken up by one kilogram of pure water at its densest, which made it about 1.000028 cubic decimeters, and that muddled definition lasted until 1964, when it was restored to exactly one cubic decimeter. A capital L was added as an alternative symbol in 1979 because a lowercase l is easy to mistake for the digit 1, and NIST says L is the symbol to use in the United States. A liter of water is close to a kilogram, which is why a one-liter bottle feels like a kilo in the hand.

The liter is the reference unit for volume on this site.

Sources: Wikipedia: Litre; NIST Guide to the SI, Chapter 5: units outside the SI

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