UK Fluid Ounces To Millilitres Converter
Convert UK imperial fluid ounces to millilitres for British recipes, drinks, medicine cups, measuring jugs and older packaging notes.
Convert UK fl oz
Converted Volume
8 UK fluid ounces converts to about 227 mL.
UK Fluid Ounce Formula
Millilitres = UK fluid ounces x 28.4130625.
UK fluid ounces = millilitres / 28.4130625.
Litres = millilitres / 1000.
US fluid ounces equivalent = millilitres / 29.5735295625.
The UK imperial fluid ounce is defined as one twentieth of an imperial pint. It is about 28.41 mL. A US customary fluid ounce is about 29.57 mL, so the two are close but not identical. For a single spoonful the difference may be small; for bottles, batches, cocktails or medicine cups, using the wrong system can become noticeable.
When To Use The UK Fluid Ounce
1British Recipes
Older UK recipes may list liquid ingredients in imperial fluid ounces. Convert to mL for modern jugs and kitchen scales.
2Imperial Pints
An imperial pint has 20 UK fluid ounces, equal to about 568 mL. This helps with milk, beer and older jug marks.
3Imported Texts
If a recipe is from the US, use a US fl oz converter instead. The country of the source matters more than the spelling.
UK fl oz To mL Table
| UK fl oz | Millilitres | Kitchen Rounding |
|---|---|---|
| 1 | 28.41 mL | 28 mL or 30 mL for rough cooking. |
| 2 | 56.83 mL | 57 mL. |
| 5 | 142.07 mL | 142 mL, or 140 mL for casual cooking. |
| 8 | 227.30 mL | 227 mL. |
| 10 | 284.13 mL | 284 mL. |
| 20 | 568.26 mL | One imperial pint. |
Worked Conversion Examples
8 UK fl oz
8 x 28.4130625 = 227.3045 mL. For a recipe, 227 mL is a sensible label. For exact lab work, keep more decimals.
250 mL To UK fl oz
250 / 28.4130625 = 8.80 UK fl oz. This is not the same as 250 mL in US fluid ounces.
20 UK fl oz
20 UK fluid ounces equals 568.26 mL, matching the imperial pint used for many UK drink measures.
Precision And Safety Notes
For cooking, whole millilitres are usually enough. For brewing, cosmetics, technical liquids or scaled recipes, use one or two decimal places and document which ounce system was used. For medicines, do not convert a dose from an old household measure unless a pharmacist, doctor or product leaflet supports that method. Use the measuring device supplied with the medicine where possible.
Be especially careful with online recipes. A page written in English may still use US measures, and a cup or pint may mean different volumes. If a source says imperial, UK or British, use this converter. If it says US, American or customary, use the US fluid ounce converter.
For drinks, remember that legal serving sizes and recipe measures are separate ideas. A bottle label may show millilitres, a traditional recipe may show imperial fluid ounces, and a bar measure may follow local licensing practice. Convert the volume first, then apply the correct serving or product rule.
UK And US Difference In Practice
The difference between UK and US fluid ounces is about 4%. That may not matter for a single splash of milk, but it can matter in a cake batter, syrup, cordial, homebrew or repeated bottle fill. If a recipe uses 20 fluid ounces, the UK version is about 568 mL while 20 US fluid ounces is about 591 mL. That is more than a tablespoon of difference.
When converting a whole recipe, identify every volume unit before changing numbers. Pints, cups, tablespoons and teaspoons can also differ by country or by convention. Keeping the source unit in your notes makes the recipe easier to repeat and audit.
For older British cookbooks, the context around the ingredient can help. Milk, water, stock, cream, vinegar and oil may be shown in imperial fluid ounces, while flour and sugar may be shown in ounces by weight. Do not convert every “oz” as a liquid. If the ingredient is dry or spooned into a scale pan, it probably needs a weight conversion or an ingredient-specific table.
For home preserving, cordial making, brewing or soap making, avoid casual rounding until the end of the recipe. Convert each original UK fluid ounce amount to millilitres, add the converted values, then round to a measuring jug or scale that suits the task. This keeps the batch closer to the original proportions.
If you are preparing a printed kitchen card, write the converted millilitres and the original UK fluid ounces side by side. That makes it easier to spot future transcription errors and lets another cook trace the number back to the original recipe. For small flavouring quantities, note whether the recipe expects level spoon measures or a measured liquid volume.
FAQ
How many mL are in 1 UK fluid ounce?
1 UK fluid ounce is exactly 28.4130625 mL.
Is a UK fluid ounce the same as a US fluid ounce?
No. A UK fluid ounce is about 28.41 mL, while a US fluid ounce is about 29.57 mL.
How many UK fluid ounces are in an imperial pint?
An imperial pint contains 20 UK fluid ounces.
Can I use this for dry ounces?
No. Fluid ounces measure volume. Dry ounces measure weight and need a different conversion.
Should I round for recipes?
Usually yes. Whole millilitres are adequate for most home cooking, but keep more precision for technical work.
Can I convert medicine doses with it?
Ask a pharmacist or clinician for medicine dosing. Use the supplied measuring device where possible.
Sources
- National Institute of Standards and Technology. (2008). Guide for the Use of the International System of Units. NIST. https://www.nist.gov/pml/special-publication-811
- International Bureau of Weights and Measures. (2019). The International System of Units (SI), 9th ed. BIPM. https://www.bipm.org/en/publications/si-brochure
- UK Weighing Federation. (n.d.). Weights and measures information. UKWF. https://www.ukwf.org.uk/