US Tablespoons to Imperial Fluid Ounces (tbsp to fl oz (UK))

1 US tablespoon equals 0.5204213654 imperial fluid ounces (rounded).

1 US tablespoon = 0.5204213654 imperial fluid ounces

How to convert US tablespoons to imperial fluid ounces

To convert US tablespoons to imperial fluid ounces, multiply the number of US tablespoons by 0.5204213654. The factor is rounded to 10 significant digits. To go the other way, multiply imperial fluid ounces by 1.921519881 (rounded).

imperial fluid ounces = US tablespoons × 0.5204213654

Example: 10 US tablespoons = 5.204213654 imperial fluid ounces.

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

US Tablespoon (tbsp)

US customaryCurrent unit

Half a US fluid ounce (14.787 mL), equal to 3 teaspoons.

A tablespoon was once a spoon first and a unit second. Tablespoons entered place settings around 1700, first reserved for soup, and in the 18th century apothecaries used an unofficial tablespoon of four fluid drams, or half a fluid ounce. That is the origin of the modern US definition, which turns the spoon into precisely half a US fluid ounce.

The US tablespoon is therefore 14.7868 milliliters, equal to three US teaspoons, and sixteen of them make a US customary cup. It is often treated as 15 mL, and American nutrition labels define a tablespoon as exactly 15 mL, so the two figures sit within about 1.4 percent of each other. The regional difference that matters is Australia, which uses a larger 20 milliliter tablespoon, so a recipe asking for a tablespoon of oil or baking powder can go wrong when translated across the Pacific.

1 US tablespoon = 0.01478676478 liters (approximately).

Sources: Wikipedia: Tablespoon; NIST SP 811, Appendix B.8: conversion factors for volume; 21 CFR 101.9: nutrition labeling household measures

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

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