Fluid Ounces to Millilitres Converter
29.57 ml per US fluid ounce, 28.41 ml per imperial one
One US fluid ounce is 29.57 millilitres. One imperial (UK) fluid ounce is 28.41 millilitres — about 4% smaller.
A US fluid ounce is 29.5735 millilitres. Round it to 30 ml and you will be within 1.5%, which is fine for cocktails, coffee and most cooking.
The imperial fluid ounce is 28.41 ml. Smaller — yet an imperial pint holds 20 of them against the US pint's 16, so imperial pints and gallons end up larger. That reversal is the source of most transatlantic recipe confusion.
Reference table
| fluid ounces | millilitres | cups | tablespoons |
|---|---|---|---|
| ½ fl oz | 14.79 ml | 0.06 cup | 1 tbsp |
| 1 fl oz | 29.57 ml | ⅛ cup | 2 tbsp |
| 2 fl oz | 59.15 ml | ¼ cup | 4 tbsp |
| 3 fl oz | 88.72 ml | ⅜ cup | 6 tbsp |
| 4 fl oz | 118.3 ml | ½ cup | 8 tbsp |
| 5 fl oz | 147.9 ml | ⅝ cup | 10 tbsp |
| 6 fl oz | 177.4 ml | ¾ cup | 12 tbsp |
| 8 fl oz | 236.6 ml | 1 cup | 16 tbsp |
| 10 fl oz | 295.7 ml | 1¼ cup | 20 tbsp |
| 12 fl oz | 354.9 ml | 1½ cup | 24 tbsp |
| 16 fl oz | 473.2 ml | 2 cup | 32 tbsp |
| 20 fl oz | 591.5 ml | 2½ cup | 40 tbsp |
| 32 fl oz | 946.4 ml | 4 cup | 64 tbsp |
US and imperial fluid ounces compared
If a recipe is British and predates metrication, assume imperial. If it is American or modern British, assume US or straight metric. When the recipe gives both a millilitre and a fluid-ounce figure, trust the millilitres.
| US | Imperial | |
|---|---|---|
| 1 fluid ounce | 29.57 ml | 28.41 ml |
| Fluid ounces per pint | 16 | 20 |
| 1 pint | 473 ml | 568 ml |
| 1 gallon | 3785 ml | 4546 ml |
| 1 cup | 8 fl oz | 10 imperial fl oz (imperial cup) |
The conversions worth having in your head
- 1 fl oz = 29.6 ml ≈ 30 ml
- 2 fl oz = 59 ml = ¼ cup
- 4 fl oz = 118 ml = ½ cup
- 8 fl oz = 237 ml = 1 cup
- 16 fl oz = 473 ml = 1 pint
- 33.8 fl oz = 1 litre
Fluid ounces in drinks
Bar measures are almost entirely in fluid ounces in the US and millilitres elsewhere. A standard US spirit pour is 1.5 fl oz, which is 44 ml. A single UK measure is 25 ml, and a double is 50 ml.
Espresso is the other place the units collide: a double shot is commonly 60 ml, which is 2 fl oz, and a 12 fl oz American coffee cup is 355 ml.
Fluid ounces are not weight ounces
A fluid ounce measures volume; a weight ounce measures mass. They match only for water, where 1 fl oz weighs about 1.04 oz.
Oil is lighter than water, so 8 fl oz of oil weighs about 7.4 oz. Honey is much heavier, so 8 fl oz weighs about 12 oz. If a recipe lists a solid in ounces, it means weight — use the grams to ounces converter instead.
Frequently asked questions
How many ml are in a fluid ounce?
A US fluid ounce is 29.57 ml. An imperial fluid ounce is 28.41 ml.
How many fluid ounces are in 100 ml?
100 ml is 3.38 US fluid ounces, or 3.52 imperial fluid ounces.
Is 30 ml the same as 1 oz?
It is close. A US fluid ounce is 29.57 ml, so 30 ml is about 1.5% more. For cooking and cocktails the rounding is harmless.
How many ml is 8 fl oz?
8 US fluid ounces is 237 ml, which is one US cup.