Ounces to ML Converter
Convert US or UK fluid ounces to millilitres, and millilitres back to fluid ounces.
Formula and sources updated · Data sources · 1View algorithm, constants and default inputs (JSON)
1 mL ≈ 0.0338140227 US fl oz
About this calculator
Fluid ounces measure volume while ounces measure weight, so they are not interchangeable. A US fluid ounce is 29.574 millilitres; the UK version is slightly smaller at 28.413 millilitres.
Worked example
calculated with the default values below
Value 8 · Direction ⇄ · Decimal places 4 · From US fluid ounces · To Millilitres (ml) Result 236.5882 · Millilitres 236.588 ml · US fluid ounces 8.0000 fl oz · UK fluid ounces 8.3267 fl oz · US cups 1.0000 cups
Method and assumptions
1 US fluid ounce = 29.5735295625 mL; 1 imperial fluid ounce = 28.4130625 mL. US customary and imperial liquid measures differ. This is volume, not ingredient mass; no density conversion is performed.
Data sources
Disclaimer
These calculators give general conversion results. Rounding and the precision of the value you enter both affect the output, so treat displayed decimals as indicative rather than exact.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
V_ml = V × {US: 29.5735295625, UK: 28.4130625}; fl oz US = V_ml ÷ 29.5735295625; cups = V_ml ÷ 236.5882365
- V
- Input value
- V_ml
- Volume in millilitres
- {US,UK}
- Selected fl oz standard
Choose the direction: US fl oz and UK fl oz use different exact factors; the reverse conversion divides by the US factor, and 1 US cup = 236.5882365 ml.
Frequently asked questions
Why is a UK fluid ounce smaller than a US fluid ounce here?
The converter uses 29.5735 ml for a US fluid ounce but only 28.413 ml for the UK (Imperial) one, so 8 US fl oz is 236.59 ml, essentially one US cup, while 8 UK fl oz is about 227.3 ml. The two systems define the ounce differently, which is why the same '8 oz' recipe can differ by roughly 9 ml depending on which you mean.
Which inputs and limits apply to Ounces to ML Converter?
Use the units shown beside each field. These are form limits, not recommended settings. Value: 0–1,000,000,000 1 US fluid ounce = 29.5735295625 mL; 1 imperial fluid ounce = 28.4130625 mL. US customary and imperial liquid measures differ. This is volume, not ingredient mass; no density conversion is performed.
What is a complete worked example for Value = 8; Direction = ⇄?
Inputs: Value = 8; Direction = ⇄; Decimal places = 4; From = US fluid ounces; To = Millilitres (ml). Calculation: V_ml = V × {US: 29.5735295625, UK: 28.4130625}; fl oz US = V_ml ÷ 29.5735295625; cups = V_ml ÷ 236.5882365. Results: Result = 236.5882 mL; US fluid ounces = 8.0000 fl oz; UK fluid ounces = 8.3267 fl oz; US cups = 1.0000 cups.