US Fluid Ounces to Microliters (fl oz to µL)

1 US fluid ounce equals 29,573.52956 microliters (rounded).

1 US fluid ounce = 29,573.52956 microliters

How to convert US fluid ounces to microliters

To convert US fluid ounces to microliters, multiply the number of US fluid ounces by 29,573.52956. The factor is rounded to 10 significant digits. To go the other way, multiply microliters by 0.0000338140227 (rounded).

microliters = US fluid ounces × 29,573.52956

Example: 10 US fluid ounces = 295,735.2956 microliters.

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)

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

Microliter (µL)

Metric (SI)Current unit

One millionth of a liter, equal to one cubic millimeter. Used for very small liquid volumes.

Older laboratory papers often call this volume a lambda, written with the Greek letter, and that name has been discouraged since 2014 in favor of the microliter. The prefix micro, meaning one millionth, entered the metric prefix list in 1873, when the symbol mu was eventually chosen because the capital M was already taken by mega. The unit therefore combines a nineteenth-century prefix with the liter.

One microliter is 10 to the minus 6 liter, which is the same volume as one cubic millimeter and one thousandth of a milliliter. Some medical test results print it as mcL instead of using the Greek letter. Small volumes like this matter wherever tiny samples are pipetted or reported, and the figure used here is exactly 0.000001 liter.

1 microliter = 0.000001 liters (exactly).

Sources: Wikipedia: Litre; Wikipedia: Metric prefix

Related conversions

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