Oz to ML Converter

Convert fluid ounces to millilitres and back, in both US and UK imperial ounces. Enter any amount, choose the precision, and check common bottle and cup sizes in the reference table.

Convert
Which fluid ounce?

Recipes and drink labels from the United States use the US ounce. British, Irish, Australian, and older Commonwealth recipes use the imperial ounce.

US fl oz
Common amounts
Decimal places
Result

236.59 ml

Formula used
Formula used: 8 × 29.5735295625 = 236.59 ml
Which fluid ounce?
Same amount in UK fl oz: 227.3 ml
Rounded to the 30 ml label ounce used on US nutrition panels: {value}
Rounded to the 30 ml label ounce used on US nutrition panels: 240 ml

Fluid ounces measure volume, dry ounces measure weight

This converter works on fluid ounces only. If a recipe asks for 8 oz of flour or cheese, that is weight, and 8 oz of flour is nowhere near 237 ml. Convert weight ounces to grams instead.

oz to ml conversion table

Common container sizes in both ounce systems, rounded to two decimal places.

Fluid ouncesUS (ml)UK (ml)Typical use
1 fl oz29.5728.41Single spirit measure
2 fl oz59.1556.83
3.4 fl oz100.5596.6Carry-on liquid limit
4 fl oz118.29113.65
5 fl oz147.87142.07
6 fl oz177.44170.48
8 fl oz236.59227.3One US cup
10 fl oz295.74284.13
12 fl oz354.88340.96Soda can
16 fl oz473.18454.61US pint
16.9 fl oz499.79480.18Standard 500 ml water bottle
20 fl oz591.47568.26
25.4 fl oz751.17721.69Wine bottle (750 ml)
32 fl oz946.35909.22US quart
64 fl oz1,892.711,818.44
128 fl oz3,785.413,636.87US gallon

Two ounces, one honest answer

Most converters pick a fluid ounce for you and never say which one. That is fine until a British recipe and an American recipe give the same number and expect different volumes. This page asks which ounce you mean, then shows the other one underneath so you can see how far apart they sit before you pour anything.

US 29.5735 ml · UK 28.4131 ml

Why use this oz to ml converter?

Both ounce systems, side by side

Switch between the US and imperial fluid ounce in one tap. Whichever you pick, the other value appears under the result so a four percent gap never catches you out.

Converts either way

Go from ounces to millilitres for a recipe, or millilitres to ounces for a bottle label. The swap button keeps the number you already typed.

Precision you control

Choose zero to four decimal places. Round figures for the kitchen, four places for lab work, dilution ratios, and anything you need to reproduce exactly.

A table for the sizes you already own

A shot, a soda can, a pint, a 750 ml wine bottle, and the 3.4 oz carry-on limit are all listed. Read the number off the page without typing anything.

How this Oz to ML Converter works

Type a number and this converter multiplies it by one fixed factor. For the US fluid ounce that factor is 29.5735295625 millilitres. For the British imperial fluid ounce it is 28.4130625 millilitres. Neither value is rounded. Each comes from a legal gallon definition: the US gallon holds 3.785411784 litres across 128 ounces, and the imperial gallon holds 4.54609 litres across 160 ounces.

The ounce you choose moves the answer by about four percent. That gap is trivial on a single shot and obvious on a full bottle, so the tool prints the other system underneath every result instead of hiding the difference. An American recipe asking for 8 fl oz means 236.59 ml. The same line in a British cookbook means 227.30 ml.

The conversion runs in both directions. Switch to millilitres and the tool divides rather than multiplies, so 100 ml comes back as 3.38 US fluid ounces, the figure behind the carry-on liquid limit at airport security.

A decimal control sets the precision. Two places suit cooking, three or four suit lab work and mixing ratios, and zero gives a number you can read at a glance.

One warning is built into the page because it causes more errors than the maths does. Fluid ounces measure volume and dry ounces measure weight. If a recipe weighs an ingredient, convert to grams instead.

Everything happens in your browser. Nothing is uploaded and no account is needed.

How to use this Oz to ML Converter

1

Pick the ounce

Choose the US fluid ounce for American recipes and drink labels, or the imperial ounce for British, Irish, and Australian sources. The two differ by about four percent.

2

Type the amount

Enter any number, or tap one of the common sizes such as 8, 12, or 16 oz. The result updates as you type, and the swap button flips the conversion to millilitres to ounces.

3

Set the precision and copy

Two decimal places suit cooking, four suit lab work. Copy the figure with one tap, or read a common size straight off the table below.

Example Usage

One US cup of milk in a recipe, shown in both ounce systems:

Input
8 fl oz
Output
US: 236.59 ml UK: 227.30 ml 8 × 29.5735 = 236.59 8 × 28.4131 = 227.30

Frequently Asked Questions

How many ml are in one fluid ounce?
One US fluid ounce is 29.5735 ml. One British imperial fluid ounce is 28.4131 ml. Neither figure is an approximation: both come straight from the legal gallon definitions, so they never change.
Why are the US and UK fluid ounces different sizes?
They were never the same unit. The imperial ounce was set in 1824 as one one-hundred-sixtieth of an imperial gallon, which Britain defined by the volume of ten pounds of water. The United States kept the older wine gallon and split it into 128 parts instead. The result is that the imperial ounce is the smaller of the two, by roughly four percent.
How many ml is 8 oz?
8 US fluid ounces is 236.59 ml, and that is what an American recipe means when it calls for one cup. 8 imperial fluid ounces is 227.30 ml. The 9 ml gap rarely matters in a stew but will show up in baking and in cocktails.
Is a fluid ounce the same as an ounce on a kitchen scale?
No, and this is the mistake that ruins recipes. A fluid ounce measures how much space something takes up. A dry ounce measures how heavy it is. Water happens to be close to both, so 8 fl oz of water weighs about 8 oz, but 8 oz of flour by weight fills roughly 430 ml. If your ingredient sits on a scale, convert to grams, not millilitres.
What is 3.4 oz in ml, and why does that number appear at airports?
3.4 US fluid ounces is 100.55 ml. Security rules cap carry-on liquids at 100 ml per container, and 3.4 oz is the closest round figure printed on American packaging. A bottle labelled 3.4 fl oz is sold as a 100 ml bottle and passes screening.
How many ounces is a 750 ml wine bottle?
750 ml is 25.36 US fluid ounces or 26.40 imperial fluid ounces. That works out to five standard 5 oz pours in the United States.
Why is a 500 ml water bottle labelled 16.9 fl oz?
500 ml is 16.907 US fluid ounces, and labels round to one decimal place. The bottle was designed in metric and the ounce figure was added afterwards, which is why the number looks so odd.
Which ounce should I use for a recipe I found online?
Check where the recipe comes from. Sites and cookbooks published in the United States mean US fluid ounces. British, Irish, Australian, and New Zealand sources mean imperial ounces, though many modern British recipes now give millilitres directly. If the recipe also lists cups, it is almost certainly American.
Does a cup always equal 8 fluid ounces?
Only in the United States. A US cup is 8 US fl oz, or 236.59 ml. An Australian metric cup is exactly 250 ml, a Japanese cup is 200 ml, and older British recipes sometimes use a 284 ml cup. Convert through millilitres rather than assuming cups match.
Can I use this to measure a medicine dose?
The arithmetic is exact, but follow the dosing device that came with the medicine rather than a kitchen spoon. Ask a pharmacist if the label and the syringe use different units. A US teaspoon on a label means 5 ml.
Why does the US nutrition label say 30 ml per ounce?
The FDA allows a rounded 30 ml serving ounce on nutrition panels to keep serving sizes readable. It is a labelling convention, not a conversion factor. For anything you actually measure, use 29.5735 ml.
Is anything I type sent to a server?
No. The conversion is one multiplication running in your browser. Nothing is uploaded, nothing is stored, and there is no limit on how many conversions you run.

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