US Fluid Ounces to Metric Teaspoons (fl oz to tsp)
1 US fluid ounce equals 5.914705913 metric teaspoons (rounded).
How to convert US fluid ounces to metric teaspoons
To convert US fluid ounces to metric teaspoons, multiply the number of US fluid ounces by 5.914705913. The factor is rounded to 10 significant digits. To go the other way, multiply metric teaspoons by 0.1690701135 (rounded).
metric teaspoons = US fluid ounces × 5.914705913
Example: 10 US fluid ounces = 59.14705913 metric teaspoons.
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 Fluid Ounce (fl oz)
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
Metric Teaspoon (tsp)
Exactly 5 mL, used in most countries.
Five milliliters is the metric teaspoon, a figure so tidy that it has become the working definition for medicine and food labels. The traditional British teaspoon was an imperial fluid drachm, one eighth of an imperial fluid ounce, about 3.55 milliliters, and the American one was 4.93 mL. US nutrition labeling law now defines a teaspoon as exactly 5 milliliters.
The 5 mL teaspoon matters most when dosing medicine. Kitchen spoons vary widely, with one Greek survey of 71 household teaspoons finding volumes from 2.5 to 7.3 mL, so measuring spoons, syringes and calibrated cups are the safer tools. It also anchors the metric cooking system: three teaspoons make a 15 mL tablespoon, and fifty fit in a 250 mL metric cup. Australia keeps a 5 mL teaspoon but counts four of them in its larger 20 mL tablespoon.
1 metric teaspoon = 0.005 liters (exactly).
Sources: Wikipedia: Teaspoon; 21 CFR 101.9: nutrition labeling household measures; Wikipedia: Metric cup
Related conversions
- Metric teaspoons to US fluid ounces (reverse)
- US fluid ounces to liters
- US fluid ounces to milliliters
- US fluid ounces to US gallons
- US fluid ounces to US cups
- US fluid ounces to cubic meters
- US fluid ounces to cubic centimeters
- US fluid ounces to US quarts
- US fluid ounces to US pints
- US fluid ounces to US tablespoons
- US fluid ounces to US teaspoons
- US fluid ounces to metric cups
- US fluid ounces to metric tablespoons
- Liters to metric teaspoons
- Milliliters to metric teaspoons
- US gallons to metric teaspoons
- US cups to metric teaspoons
- Cubic meters to metric teaspoons
- Cubic centimeters to metric teaspoons
- US quarts to metric teaspoons
- US pints to metric teaspoons
- US tablespoons to metric teaspoons
- US teaspoons to metric teaspoons
- Metric cups to metric teaspoons
- Metric tablespoons to metric teaspoons
See all volume units.