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

1 US tablespoon equals 0.5 US fluid ounces exactly.

1 US tablespoon = 0.5 US fluid ounces

How to convert US tablespoons to US fluid ounces

To convert US tablespoons to US fluid ounces, multiply the number of US tablespoons by 0.5. This factor is exact. To go the other way, multiply US fluid ounces by 2.

US fluid ounces = US tablespoons × 0.5

Example: 10 US tablespoons = 5 US 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

US Fluid Ounce (fl oz)

US customaryCurrent unit

One 128th of a US gallon, 29.5735 mL. Not the same as the weight ounce, and about 4% larger than the imperial fluid ounce.

Fluid ounce began as an attempt to link volume to weight: the volume occupied by one ounce of some substance, such as wine in England or water in Scotland. Definitions varied by region and by liquid. When Britain defined its imperial gallon in 1824 as the space of ten pounds of water, the imperial fluid ounce came out so that an ounce of water weighs about one avoirdupois ounce. The US fluid ounce followed a different path and comes from the older wine gallon.

The US fluid ounce is exactly 1/128 of a US gallon, 29.5735295625 milliliters, about 4 percent bigger than the imperial one at 28.4130625 milliliters. American nutrition labels use yet another figure, treating one fluid ounce as 30 milliliters, a convenient rounding for serving sizes. The name is a trap, because a fluid ounce measures space while a weight ounce measures mass. A US fluid ounce of water weighs a bit more than an ounce of weight, while a fluid ounce of honey weighs considerably more.

1 US fluid ounce = 0.02957352956 liters (approximately).

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

Related conversions

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