About

Cubic centimeters (cc) and fluid ounces (fl oz) measure volume in fundamentally different systems. 1 cc equals exactly 1 mL, but its relationship to fluid ounces depends on which ounce you mean. The US fluid ounce is 29.5735 mL. The Imperial fluid ounce is 28.4131 mL. Confusing the two creates a 4% dosing error in pharmaceuticals or a measurable deviation in laboratory titrations. This tool converts between cc, US fl oz, Imperial fl oz, milliliters, liters, tablespoons, and teaspoons using NIST-traceable conversion factors.

Precision matters in medical contexts where syringes are graduated in cc but oral medication instructions reference fl oz. A rounding error on a 5 cc pediatric dose can exceed safe margins. This converter carries 6 significant digits and flags when you are working across US and Imperial systems. Note: all conversions assume standard liquid volume at sea-level atmospheric pressure. Volumes of gases or compressed fluids require density corrections not covered here.

Formulas

All conversions route through milliliters (mL) as the canonical base unit. Since 1 cc ≡ 1 mL by definition, the general conversion formula is:

result = value × f_fromf_to

Where f_from is the factor converting the source unit to mL, and f_to is the factor converting mL to the target unit. For the primary cc → US fl oz conversion:

fl oz_US = cc × 129.5735 ≈ cc × 0.033814

And for cc → Imperial fl oz:

fl oz_Imp = cc × 128.4131 ≈ cc × 0.035195

Where value = numeric input, f_from = mL-equivalent of source unit, f_to = mL-equivalent of target unit. The conversion factors are NIST-derived constants (NIST SP 811). Results are rounded to 6 significant figures to prevent floating-point display artifacts.

Reference Data

Unit	Abbreviation	Equivalent in mL	Equivalent in US fl oz	System	Common Use
Cubic Centimeter	cc	1	0.033814	Metric	Medical syringes, engines
Milliliter	mL	1	0.033814	Metric	Lab measurements, recipes
US Fluid Ounce	US fl oz	29.5735	1	US Customary	Beverage labels, cooking
Imperial Fluid Ounce	Imp fl oz	28.4131	0.96076	Imperial	UK recipes, pharmacies
US Tablespoon	US tbsp	14.7868	0.5	US Customary	Cooking, medicine
US Teaspoon	US tsp	4.92892	0.166667	US Customary	Cooking, medicine
Imperial Tablespoon	Imp tbsp	17.7582	0.600475	Imperial	UK cooking
Imperial Teaspoon	Imp tsp	5.91939	0.200158	Imperial	UK cooking
Liter	L	1000	33.814	Metric	Beverages, fuel
Deciliter	dL	100	3.3814	Metric	European recipes
Centiliter	cL	10	0.33814	Metric	Wine measures
US Cup	US cup	236.588	8	US Customary	Cooking
Imperial Cup	Imp cup	284.131	9.6076	Imperial	UK cooking
US Pint	US pt	473.176	16	US Customary	Beverages
Imperial Pint	Imp pt	568.261	19.2152	Imperial	UK beer
US Quart	US qt	946.353	32	US Customary	Motor oil
US Gallon	US gal	3785.41	128	US Customary	Fuel, bulk liquids
Imperial Gallon	Imp gal	4546.09	153.722	Imperial	UK fuel
Cubic Inch	in³	16.3871	0.554113	US/Imperial	Engine displacement
Drop (medical)	gtt	0.05	0.00169	Medical	IV drip, eye drops

Frequently Asked Questions

They are identical in practice. 1 cc = 1 mL = 1 cm³. The cubic centimeter (cc) is the CGS unit, the milliliter (mL) is the SI-accepted unit, and cm³ is the derived SI notation. Medical and automotive industries prefer "cc", while chemistry and cooking prefer "mL". The equivalence holds exactly at standard conditions: 1 cc of water at 4 °C weighs 1 gram.

A US fluid ounce equals 29.5735 mL while an Imperial fluid ounce equals 28.4131 mL - a 4.08% difference. In pharmaceutical dosing, this gap can push a measurement outside the therapeutic window. In baking, it accumulates across multiple ingredients. When a recipe or prescription says "oz", you must know which system applies. US fl oz is standard in North America. Imperial fl oz is used in the UK, Canada (historically), and some Commonwealth nations.

All factors derive from NIST Special Publication 811 and the International Bureau of Weights and Measures (BIPM). The US fluid ounce is defined as exactly 1/128 of a US gallon, where 1 US gallon = 3.785411784 L exactly. The Imperial fluid ounce is 1/160 of an Imperial gallon, where 1 Imperial gallon = 4.54609 L exactly. The tool preserves up to 6 significant figures in displayed results.

The volume conversion factors are geometric constants and do not change with temperature. However, if you are converting mass-based measurements (e.g., 'ounces by weight') to volume, the liquid's density becomes critical and density varies with temperature. For example, water at 25 °C has a density of 0.99707 g/mL versus 1.00000 g/mL at 4 °C. This converter handles volume-to-volume only and does not account for density.

Engine displacement in cc converts to cubic inches by dividing by 16.387064. A 1000 cc engine is approximately 61.02 in³. This converter includes cubic inches (in³) as a selectable unit. Note that automotive "cc" ratings often represent swept volume (bore × stroke × number of cylinders) and are nominal values, not exact geometric measurements.

For doses under 10 mL (10 cc), use at least 2 decimal places. For doses above 10 mL, 1 decimal place suffices per USP General Chapter 1176 guidelines. Always verify against the medication's prescribing information. This tool provides up to 6 significant digits, but clinical practice rounds to the nearest graduation mark on the syringe or measuring device being used. A standard 1 mL syringe has 0.01 mL graduations; a 60 mL syringe has 1 mL graduations.