Article — mL to Oz Converter
To convert ml to oz, divide the milliliters by 29.5735. That's for US fluid ounces. UK Imperial? Divide by 28.4131. Or divide by 30 if you're in a hurry and can live with being off by about 1.4%. Most people googling "ml to oz" just need a quick answer for one specific number, and we've listed the common ones below so you can skip the math entirely.
The ml to oz conversion formula
One division. Milliliters go in, fluid ounces come out.
US fluid ounces = mL ÷ 29.5735UK fluid ounces = mL ÷ 28.4131Reverse (oz to mL) = fl oz × 29.5735 (US)Where does 29.5735 come from? The US gallon is defined as exactly 3,785.411784 mL. There are 128 fluid ounces in a gallon. Divide those two and you get 29.5735295625 mL per fluid ounce. It traces back to the legal definition of a US gallon, so the number isn't arbitrary even though it looks like one.
The UK version uses different starting numbers. An Imperial gallon is 4,546.09 mL, divided into 160 fluid ounces, which gives 28.4130625 mL per ounce.
Ml to oz quick reference table
These are the ml to oz conversions people actually search for. If your number is here, you're done.
5 mL = 0.17 oz (1 teaspoon)15 mL = 0.51 oz (1 tablespoon)30 mL = 1.01 oz (shot glass)100 mL = 3.38 oz (TSA limit)237 mL = 8.01 oz (1 US cup)250 mL = 8.45 oz (1 metric cup)330 mL = 11.16 oz (EU soda can)355 mL = 12.00 oz (US soda can)500 mL = 16.91 oz (half liter)750 mL = 25.36 oz (wine bottle)1000 mL = 33.81 oz (1 liter)355 mL converts to exactly 12.00 oz, which is not a coincidence. American soda cans were designed around 12 fluid ounces, and 355 mL is that measurement in metric. The European 330 mL can went the other direction: it started as a round metric number and lands on the less tidy 11.16 oz.
US vs UK fluid ounces in ml to oz
There are two fluid ounces in the world and they're different sizes. If you use an ml to oz converter without checking which system it defaults to, you could be off by about 4%.
The US fluid ounce is bigger, but the UK gallon is bigger. Sounds contradictory, but the math makes sense: the US gallon (3,785 mL) splits into 128 ounces, while the UK gallon (4,546 mL) splits into 160. More slices of a bigger pie means each slice ends up smaller.
At 500 mL the gap is already noticeable: 16.91 US fl oz versus 17.60 UK fl oz. Almost a full ounce apart. For a single drink, who cares. For a recipe calling for 6 cups of liquid, that error adds up.
If a recipe or product label doesn't say US or UK, assume US. American fluid ounces dominate online recipes, food packaging, and most ml to oz converters. UK Imperial fluid ounces mostly turn up in older British cookbooks and pub measures.
Ml to oz mental math shortcut
No calculator handy? Divide the milliliters by 30. Not exact, but close enough for cooking and grocery shopping.
100 mL ÷ 30 = 3.3 oz (actual: 3.38)250 mL ÷ 30 = 8.3 oz (actual: 8.45)500 mL ÷ 30 = 16.7 oz (actual: 16.91)750 mL ÷ 30 = 25.0 oz (actual: 25.36)1000 mL ÷ 30 = 33.3 oz (actual: 33.81)It undershoots by about 1.4% because 30 is slightly bigger than 29.5735. A 750 mL wine bottle gives you 25 oz instead of 25.36. Nobody's going to notice that at a dinner party. For medication dosing, though, use the real number.
Ml to oz for travel: the TSA 100 mL rule
A huge chunk of "ml to oz" searches come from people packing for a flight. TSA's 3-1-1 rule caps each carry-on container at 3.4 oz, which is 100 mL. Everything has to fit in one quart-size bag.
TSA screens roughly 900 million passengers per year. Millions of liquid containers get tossed because they're over the 100 mL / 3.4 oz limit. European airports enforce the same restriction but label it 100 mL, not 3.4 oz, which causes fewer mix-ups because nobody has to convert anything.
3.4 oz is a rounded conversion of 100 mL. The precise number is 3.3814 oz, but TSA rounds up to keep things simple. A 100 mL bottle will clear security. A 110 mL bottle probably won't.
Ml to oz in medicine and dosing
Medicine is one area where sloppy ml to oz conversion actually hurts people. American drug labels often list doses in milliliters and teaspoons, but a 2014 study in Pediatrics found that parents using kitchen teaspoons to measure children's liquid medication made dosing errors 42.5% of the time. Parents using milliliter syringes still got it wrong 27.6% of the time, but that's a meaningful improvement.
The American Academy of Pediatrics now recommends dosing all liquid medications in milliliters only. Plenty of over-the-counter drugs in the US still print "teaspoons" on the label anyway.
The FDA lets food labels round 1 fl oz to 30 mL, but the actual value is 29.5735 mL. In cooking, 0.4 mL is nothing. In medication for infants, it might matter. Use the measuring device that came with the medicine, and stick to milliliters.
Why soda cans make ml to oz confusing
A soda can isn't the same size everywhere. That's a weird thing to realize if you've never thought about it.
None of these are conversions of each other. The American can started with ounces. Everyone else started with milliliters. Each country picked a round number in their own system, which is why the sizes don't match up.
Common ml to oz mistakes
Milliliters measure volume. Milligrams measure mass. They're only equal for water: 1 mL of water weighs about 1,000 mg. But 1 mL of honey weighs around 1,420 mg, and 1 mL of olive oil about 920 mg. If a recipe says "5 mg," that's not "5 mL" unless the ingredient is water.
8 fluid ounces of water weighs about 8.35 ounces by weight. Close, but not the same. The gap widens for denser liquids: 8 fl oz of honey weighs about 11.5 oz. "Oz" on a food package almost always means weight. "Fl oz" means volume. When converting ml to oz, you want fluid ounces.
500 mL is 16.91 US fl oz but 17.60 UK fl oz. Almost a full ounce apart. For one drink, it doesn't matter. For a recipe calling for 6 cups of liquid, the error compounds fast. Check which system you need before converting.