Article — CC to Oz Converter
CC to Oz: from Syringe to US Fluid Ounce
One cubic centimetre equals 0.0338140227 US fluid ounces, exactly. The converter handles both directions and rounds to four decimal places by default. The factor is exact because 1 cc = 1 mL by definition, and the US fluid ounce is defined as 29.5735295625 mL. Dividing one by the other returns the cc-to-oz conversion factor with no measurement uncertainty.
Most queries that reach a cc to oz converter come from one of three places: a medical context (syringe markings, dose cups, IV bags), an engineering context (engine displacement, fuel-system specs), or a kitchen context (US recipes meeting metric measuring jugs). The math is the same in all three.
CC equals mL, by definition
A cubic centimetre is the volume of a 1 cm cube. A millilitre is one thousandth of a litre, and a litre is defined as exactly 1000 cubic centimetres, so 1 mL equals 1 cc exactly. The two units are interchangeable everywhere: hospitals, chemistry labs, syringe manufacturers, and automotive specifications use them as synonyms.
Both names persist for historical reasons. The original 1795 metric system used the cubic centimetre; the litre was added later as a more practical everyday unit. Modern SI prefers mL for liquid measure and cm3 for solid volume, but cc remains universal in medicine and automotive engineering.
The cc abbreviation came from the German Kubikzentimeter via 19th-century medical and pharmaceutical practice. American hospitals adopted it from German-trained physicians in the late 1800s, and it survived the metric-to-mL renaming wave of the 1970s mainly because it was already printed on every syringe barrel in every American hospital.
The cc to oz conversion factor
The factor 0.0338140227 is exact to the digits shown. It comes from the US fluid ounce, defined as 1/128 of a US gallon, where the US gallon is exactly 231 cubic inches. Working through the chain: 231 cubic inches converts to 3,785.411784 cubic centimetres, divided by 128 fluid ounces gives 29.5735295625 cc per fluid ounce. The reciprocal is 0.0338140227 fluid ounces per cc.
For mental math, 30 cc is close enough to 1 fluid ounce that medicine cups print 30 cc as the 1 fl oz mark. The actual error is 29.57 vs. 30, or about 1.4%, which sits below the precision medical dosing actually targets. For lab work that needs better than 1% accuracy, use the full factor.
1 cc = 0.034 fl oz5 cc (1 tsp) = 0.17 fl oz15 cc (1 tbsp) = 0.51 fl oz30 cc (1 dose cup) = 1.01 fl oz100 cc = 3.38 fl oz1000 cc (1 L) = 33.81 fl ozSyringe markings and cc to oz dosing
Syringe barrels in the US are graduated in cc, not fluid ounces. A 1 cc tuberculin syringe, a 3 cc standard syringe, a 10 cc syringe, a 60 cc enteral feeding syringe — the size description and the barrel marks all use cc. The reason is clinical safety: fluid ounces and weight ounces share a name, and any unit that can be confused with weight in a pharmacy is unsafe.
A US medicine cup is marked in both cc and fluid ounces, with cc as the primary scale. The rim line is at 30 cc, equal to 1 US fluid ounce, two tablespoons, or six teaspoons. The teaspoon mark sits at 5 cc; the tablespoon mark sits at 15 cc.
If a prescription label or label warns to take 1 ounce of liquid medication, it always means 1 fluid ounce (29.57 mL, or about 30 cc). A weight ounce (28.35 g) is a unit of mass and applies to dry medications, not liquids. Confusion between the two has caused real dosing errors. Medical practice avoids the ambiguity by using cc or mL exclusively for liquids.
Engine displacement: cc to oz of capacity
Internal combustion engines are sized by displacement, the total volume swept by all pistons in one complete operating cycle (two crankshaft revolutions for a 4-stroke engine). A 2,000 cc engine has a displacement of 2.0 litres, equivalent to 122 cubic inches or 67.63 US fluid ounces. The fluid-ounce expression turns up in US service manuals for oil and coolant capacities.
A typical motorbike runs 50 cc to 1,200 cc. Compact cars run 1,000 to 1,600 cc; mid-size cars 1,800 to 2,500 cc; full-size US trucks 4,000 to 6,000 cc. The cc-to-fluid-ounce factor of 0.034 is useful for cross-referencing US oil-fill specs against European cc-marked dipsticks.
US fluid ounce vs. imperial fluid ounce
The US fluid ounce equals 29.5735 mL. The imperial (UK) fluid ounce equals 28.4131 mL. The two units are within 4% of each other but they are not the same, and the conversion factor changes depending on which one you mean. This calculator uses the US fluid ounce, which is the standard in US pharmacy, US food packaging, and most international commerce.
For UK recipes and British pharmacy contexts (which still occasionally use imperial fluid ounces despite the official metric transition), the conversion factor is 0.035195 instead of 0.033814. The difference matters in two cases: scaling a British pre-1970 recipe and reading bottle labels for products manufactured for the UK market.
If you are converting cc to oz for a recipe and the recipe is American, use 0.0338. If the recipe is British and predates metrication (so the fl oz on the page is imperial), use 0.0352. For any recipe written after 1980 the underlying unit is almost certainly metric and the conversion may be unnecessary.
Fluid ounce vs. weight ounce
The fluid ounce is a volume unit; the weight ounce (avoirdupois ounce) is a mass unit. They share a name but measure different physical quantities. The US fluid ounce is 29.5735 mL; the avoirdupois ounce is 28.3495 g. Water at room temperature happens to weigh almost exactly one weight ounce per fluid ounce, which is the historical reason for the shared name — but for any other substance the two values diverge.
One fluid ounce of honey weighs 1.42 oz on a kitchen scale because honey is 42% denser than water. One fluid ounce of olive oil weighs 0.92 oz because oil is lighter than water. The cc to oz converter on this page handles only the volume case; for volume-to-weight conversions a density factor is required.
Common cc to oz mistakes
The first cc to oz mistake is confusing fluid ounces with weight ounces, especially in cooking contexts where both turn up. A US recipe that calls for 4 oz of butter means 4 weight ounces (113 g); a recipe that calls for 4 oz of milk usually means 4 fluid ounces (118 cc). Context tells which one.
The second is using the imperial factor (0.0352) when the recipe or label is American. The two factors differ by 4%, which is below the precision of most kitchen scales but above the precision of pharmacy dosing.
The third is mixing the cc-to-mL identity with the cc-to-fl-oz conversion. The first is exact equality; the second is a factor of about 30. 100 cc equals 100 mL exactly, but 100 cc equals only 3.38 US fluid ounces. Skipping the multiplication produces an answer that is wrong by a factor of 30.