Convert Fluid Ounces (US) to Milliliters

How to convert fluid ounces to milliliters

One US fluid ounce equals 29.5735295625 mL exactly — it is defined as 1/128 of the US gallon, and the gallon itself is fixed at 231 cubic inches. The everyday factor is 29.5735.

1. Take the fluid-ounce amount.
2. Multiply by 29.5735.
3. Round sensibly for the task — a bar pour needs less precision than a medicine dose.

Worked example: a 12 fl oz soda can contains 354.8824 mL. The factor scales linearly, so 10 fl oz comes to 295.7353 mL.

What is a fluid ounce (US)?

The US fluid ounce is the small liquid unit of the US customary system: 1/128 of a gallon, or 29.5735295625 mL exactly. It appears on American drink cans, cocktail recipes, cosmetics, and over-the-counter medicine labels. Two warnings apply — it is not the ounce used for weight, and it is not quite the same as the slightly smaller imperial fluid ounce found on older UK packaging.

What is a milliliter?

Milliliters are how the rest of the world labels small liquid volumes. The unit is a thousandth of a liter — the milli- prefix is standardized in the BIPM’s SI Brochure — and since the liter is one cubic decimeter, the milliliter slots exactly into the wider metric system. Syringes, perfume bottles, and beverage cans outside the US are all marked in mL.

When you’ll need fluid ounces to mL

• Cocktail recipes with a metric jigger: American bar books pour in fluid ounces. A 2 fl oz spirit measure is 59.1471 mL, and a 0.5 fl oz accent of liqueur is 14.7868 mL on a mL-marked jigger.
• Airport liquid limits: carry-on rules cap containers at 100 mL, which is 3.3814 fl oz. A 3 fl oz bottle (88.7206 mL) clears the limit; a 4 fl oz bottle (118.2941 mL) gets confiscated at security.
• Medicine dosing: dosing syringes and cups are usually graduated in milliliters. If the instructions specify 1 fl oz of a liquid remedy, that is 29.5735 mL on the syringe.
• Reading drink sizes: the American 20 fl oz bottle holds 591.4706 mL, and the classic 12 fl oz can is 354.8824 mL — numbers worth knowing when comparing serving sizes against metric labels.
• Cosmetics and toiletries: US-made lotions and fragrances are labeled in fl oz first. A 2.5 fl oz bottle contains 73.9338 mL, which is the figure most non-US customs and shipping forms want.