A ml to oz calculator converts a metric volume to US fluid ounces using the exact factor 1 mL = 0.033814 fl oz. Enter the milliliter value and the calculator returns the fluid ounce equivalent.
Useful for translating cocktail recipes (most are written in oz in the US, mL or cl in metric countries), reading metric food and beverage labels in the US, dosing children's liquid medication (always metric for safety), and any setting where the same liquid volume needs both unit systems.
Key takeaway
A milliliter is roughly 1/30th of a US fluid ounce. The convenient anchor: a standard "shot" of 1.5 fl oz ≈ 44 mL, and 30 mL ≈ 1 fl oz. Be aware that fluid ounces are different from weight ounces: 1 fl oz of water happens to weigh ~1 oz, but 1 fl oz of olive oil weighs ~0.91 oz. Always check whether a recipe uses fluid (volume) or weight ounces.
How it's calculated
The conversion:
US fluid oz = milliliters × 0.033814
Equivalently, mL ÷ 29.5735. The 29.5735 mL per fluid ounce comes from the US gallon's exact definition (3.785411784 L = 128 fl oz, so 1 fl oz = 29.5735 mL).
Imperial fluid ounces (UK/Commonwealth historical) are slightly different: 1 imperial fl oz = 28.4131 mL. Imperial gallons divide into 160 fl oz (vs. US's 128), making each imperial fluid ounce a bit smaller. Most modern UK recipes are metric; imperial fluid ounces show up mostly in legacy contexts.
Useful anchor points:
- 5 mL = 1 teaspoon (medicine dosing)
- 15 mL = 1 tablespoon = 0.5 fl oz
- 30 mL ≈ 1 fl oz (close enough for most kitchen use)
- 240 mL ≈ 1 cup = 8 fl oz
- 355 mL = 12 fl oz (US soda can)
- 500 mL ≈ 17 fl oz (large beverage bottle)
- 750 mL ≈ 25.4 fl oz (standard wine bottle)
Source: NIST exact conversion, 1 mL = 0.033814 US fluid oz
Examples
250 mL, large drinking glass
- Volume 250 mL
250 mL converts to 8.45 fl oz, close to a standard US cup (8 fl oz exactly). European drinking glasses commonly come in 200, 250, and 300 mL sizes; the 250 is roughly equivalent to the standard US "1 cup" measure that recipes assume.
750 mL, standard wine bottle
- Volume 750 mL
A 750 mL wine bottle is 25.36 fl oz, slightly more than 3 US cups (24 fl oz). At 5-oz standard pours, that's about 5 glasses per bottle. Some restaurants pour 6-oz "generous" servings, getting closer to 4 glasses per bottle.
Frequently asked questions
How do I convert ml to fluid ounces?
Multiply by 0.033814 for the exact answer, or divide by 30 for a quick mental estimate (within ~1.5%). So 250 mL ÷ 30 ≈ 8.3 fl oz (actual: 8.45). The 30:1 ratio is the kitchen-and- bartender shortcut; for medicine and chemistry, use the precise 0.033814 factor.
Is a fluid ounce the same as a weight ounce?
No, but they're close for water. A US fluid ounce is a volume (29.57 mL); a weight ounce is a mass (28.35 g). For water, 1 fl oz weighs ~29.57 g (1.04 oz), close enough to share the same name. For oil, syrup, alcohol, and any non-water liquid, fluid ounces and weight ounces give different numbers. Always check whether a recipe specifies fluid or weight ounces; mismatches cause real cooking errors.
What's the difference between US and imperial fluid ounces?
A US fluid oz = 29.5735 mL. An imperial fluid oz = 28.4131 mL, about 4% smaller. The difference comes from imperial vs. US gallon definitions (128 vs. 160 fluid ounces per gallon). Imperial fluid ounces show up in older UK references and some Commonwealth countries. Modern UK retail is metric. When in doubt, assume US fluid ounces in US recipes; imperial in UK historical contexts.
How do metric and US recipe measures compare?
Common kitchen anchors: 5 mL = 1 tsp, 15 mL = 1 tbsp, 240 mL ≈ 1 cup (the US cup is 236.6 mL exactly, so the rounded 240 is close). 1 liter ≈ 4 cups + 4 tsp (1 L = 33.81 fl oz = 4.227 cups). For baking, weighing ingredients in grams is more accurate than measuring volumes, flour can vary 20% by weight depending on how you scoop it.