Article — Oz to CC Converter
Oz to CC converter: the exact 29.5735 factor for fluid ounces and cubic centimeters
An oz to cc converter swaps US fluid ounces for cubic centimeters with one exact factor: 1 fl oz = 29.5735 cc. Since 1 cc = 1 mL exactly, the same number works for milliliters. 8 fl oz (one US cup) = 236.59 cc. 16 fl oz (one US pint) = 473.18 cc. 32 fl oz (one US quart) = 946.35 cc. The factor is exact, not measured, derived from the US gallon definition of 231 cubic inches divided by 128 fluid ounces. There is no rounding in the conversion itself, only in the input value.
The default 1 fl oz = 29.57 cc covers a standard shot. Quick-pick buttons cover the most common pharmacy and kitchen volumes from 0.5 fl oz to 32 fl oz. The reverse direction (cc to fl oz) uses the reciprocal factor 0.033814.
The oz to cc formula
CC = fluid ounces times 29.5735. Fluid ounces = cc times 0.033814 (the reciprocal). The factor 29.5735295625 is exact. Derivation: 1 US gallon = 231 cubic inches (legal definition since 1832); 1 US gallon = 128 fluid ounces; so 1 fl oz = 231 / 128 = 1.8046875 cubic inches. Then 1 in cubed = (2.54 cm) cubed = 16.387064 cubic centimeters. Multiply: 1.8046875 times 16.387064 = 29.5735295625 cc. Every digit is exact because the inputs are exact.
1 fl oz = 29.57 cc standard shot2 fl oz = 59.15 cc double shot8 fl oz = 236.59 cc 1 US cup12 fl oz = 354.88 cc soda can16 fl oz = 473.18 cc 1 US pint32 fl oz = 946.35 cc 1 US quartOz to cc for syringes
Most US syringes are marked in cc rather than fluid ounces, because medical practice everywhere uses metric volume. A 1 oz syringe holds 29.57 cc; manufacturers usually round the label to 30 cc. A 2 oz syringe is 60 cc; a 4 oz feeding syringe is 120 cc. The graduation lines on a 10 cc syringe sit at 0.5 cc spacing, and on a 60 cc syringe at 2 cc spacing. Reading in cc avoids the rounding errors that creep in when converting on the fly at the bedside.
The "cc" label on syringes is a holdover from 19th-century chemistry. The 1879 Comite International des Poids et Mesures defined the cc as the volume of a cube 1 cm on each side. The mL came later, when the liter was redefined in terms of the kilogram-of-water standard. Today the two units are identical to all decimal places, but the cc notation stuck in medical practice and in engine specifications.
Oz to cc in pharmacy
US pharmacy reads in two unit systems at the same desk: ounces (and teaspoons, tablespoons) on the consumer label, cc/mL on the dispensing equipment. Standard dose-cup markings: 5 cc = 1 teaspoon; 15 cc = 1 tablespoon; 30 cc = 1 fluid ounce. The 1.4 percent rounding (29.57 to 30) is acceptable because pharmacy dosing targets a wider safety margin. For high-potency drugs, the dispensing syringe is calibrated to the exact cc value and the conversion is done by the pharmacist in advance.
USP (US Pharmacopeia) standards specify dosing accuracy to plus or minus 10 percent. The 1.4 percent error from using 30 cc per fl oz is well within tolerance. For sensitive applications (pediatric, neonatal, chemotherapy), pharmacists override the round number and use 29.5735 directly.
Oz to cc in the kitchen
US recipes mix fluid ounces, cups, and tablespoons. Converting to metric for accurate baking: 1/4 cup = 2 fl oz = 59 cc; 1/3 cup = 79 cc; 1/2 cup = 118 cc; 2/3 cup = 158 cc; 3/4 cup = 177 cc; 1 cup = 237 cc. The rounding to whole cc is acceptable for cooking. For baking, especially gluten-free or sourdough work, use the full precision 29.5735 cc per fl oz to avoid drift over multiple ingredients.
Oz to cc and engine displacement
Engine displacement is the total volume swept by all pistons in one cycle. The standard unit worldwide is cc (or L for larger engines), even in the US where marketing literature lists fl oz almost never. A 600 cc motorcycle engine displaces 20.29 fl oz. A 2.0 liter (2000 cc) car engine displaces 67.63 fl oz. The fluid-ounce form is mostly a curiosity, but it shows up in capacity charts for engine oil, coolant, and transmission fluid. A typical 2.0 L engine takes about 5 quarts (160 fl oz, 4730 cc) of oil at service.
US vs UK fluid ounce
The US and UK fluid ounces are different sizes. 1 US fl oz = 29.5735 cc. 1 UK (imperial) fl oz = 28.4131 cc. The US ounce is 4 percent larger. A US pint is 16 fl oz (473 cc); a UK pint is 20 imperial fl oz (568 cc). When converting a UK recipe, multiply imperial fl oz by 28.4131, not 29.5735. The two unit systems do not interoperate without explicit conversion. This converter uses the US fluid ounce, the standard in US pharmacy, packaging, and recipe formats.
Oz weight vs fl oz volume
Ounce (oz) alone usually means weight; fluid ounce (fl oz) always means volume. The two are different physical quantities. 1 oz weight = 28.35 g. 1 fl oz volume = 29.57 cc. The numerical similarity is a historical coincidence: the British system originally defined the fluid ounce as the volume of one ounce-weight of water at a specific temperature. The two values drifted apart with later redefinitions. For dosing or recipes, always check whether the spec says oz or fl oz.
1 fl oz of water weighs roughly 1 oz. 1 fl oz of cooking oil weighs 0.92 oz. 1 fl oz of honey weighs 1.42 oz. The volume-to-weight equivalence only holds for water and dilute aqueous solutions. For other liquids, multiply by the density. This converter handles volume only.
Common oz to cc mistakes
The first mistake is rounding 29.5735 to 30 in critical applications. The 1.4 percent error is fine for kitchen cooking and consumer-grade dosing, but inappropriate for pharmacy compounding, laboratory volumetrics, or any procedure where small volumes accumulate into a single batch. Always use the full precision in chained calculations.
The second mistake is mixing US and UK fluid ounces in the same recipe. Old British cookbooks use imperial; newer ones use metric. When in doubt, check whether the cup is 8 fl oz (US, 237 cc) or 10 fl oz (UK, 284 cc). The difference is substantial across a multi-ingredient bake.