How to convert millilitres to fluid ounces, US and UK.
A US fluid ounce is 29.5735 mL and a UK one 28.4131 mL. How to convert ml to fl oz and back, and why labels say 30 mL.
By Suraj Kumar3 min read
Fluid ounces come in two sizes, and US food labels use a third, rounded one. Here is which is which.
US and UK fluid ounces.
A US fluid ounce is 1/128 of a US gallon, exactly 29.5735295625 mL. A UK fluid ounce is 1/160 of a UK gallon, exactly 28.4130625 mL. 250 mL is about 8.45 US fl oz or 8.80 UK fl oz.
Why labels say 30 mL.
For nutrition labels, US rules round a fluid ounce to 30 mL and a cup to 240 mL. The converter uses the exact customary measures, and the label cup is there if you type label cup.
Which one the converter reads.
Typing oz with ml as the target reads a US fluid ounce, and the page says so with a button for the UK one. Under More options, choose UK to read UK measures throughout.
Further reading
Topics: ml to oz · oz to ml · ml to fl oz · fluid ounces to ml · how many ml in an ounce · us fluid ounce
A little less theory. A little more doing.
Try it on your own terms, with a free browser tool.
Try the tool