cc and mL: The Same Volume, Two Names
A cubic centimeter (cc) and a milliliter (mL) are exactly the same volume. There is no conversion factor, no rounding, and no approximation involved: 1 cc = 1 mL, always. This is not a close approximation — it is a definitional equality established by the International System of Units (SI).
So why does this converter exist? Because many people encounter one unit in a specific context (for example, "cc" on a syringe) and need to confirm that it matches the other unit (for example, "mL" in a recipe or lab protocol). This page serves as that confirmation and explains the history behind both terms.
The History Behind Two Identical Units
The cubic centimeter was defined first. It comes directly from the metric system: take a cube that is 1 centimeter on each side, and the volume inside it is 1 cubic centimeter (1 cm³ or 1 cc). This definition has been part of the metric system since it was established in France in the 1790s.
The liter was originally defined as the volume of 1 kilogram of water at its maximum density (about 4°C). A milliliter, being one-thousandth of a liter, was therefore the volume of 1 gram of water — which turned out to be almost exactly 1 cubic centimeter. In 1964, the General Conference on Weights and Measures officially declared that 1 mL equals exactly 1 cm³, eliminating any tiny historical discrepancy.
Where You Will See "cc" Used
Medical and pharmaceutical settings are the most common context for cc. Syringes, IV drip rates, medication dosages, and blood test volumes are frequently expressed in cc. A standard insulin syringe might be labeled as a "1 cc syringe," holding exactly 1 mL of fluid. While modern medical guidelines encourage the use of mL, decades of tradition mean cc remains widespread in hospitals, clinics, and nursing education.
Automotive and motorcycle industries use cc to describe engine displacement — the total volume swept by all pistons in one complete engine cycle. A "250cc motorcycle" has an engine whose cylinders displace a combined volume of 250 cubic centimeters (250 mL, or 0.25 liters). Engine displacement directly relates to power output, so cc has become shorthand for engine size and capability.
Scientific research historically used cc in chemistry and physics papers. While modern scientific writing prefers mL as the SI-standard notation, older textbooks and publications frequently use cc. If you are reading research from before the 1990s, you will commonly encounter cc.
Why Both Terms Persist
Given that cc and mL are identical, you might wonder why both terms still exist. The answer lies in convention and context. Each field has its own vocabulary, and switching terminology takes decades. Doctors trained with cc continue to use it and teach it to new staff. Motorcycle enthusiasts discuss engine size in cc because that is how manufacturers have always specified it. Meanwhile, cooking, food science, and modern chemistry have standardized on mL.
Neither term is wrong. Using cc or mL is a matter of audience and convention, not accuracy. However, in medical contexts, major organizations like the Joint Commission have recommended using mL to avoid potential confusion with other abbreviations, particularly in handwritten prescriptions where "cc" could be misread.
Related Conversions
Since 1 cc = 1 mL, other volume relationships apply equally to both units:
- 1000 cc = 1000 mL = 1 liter
- 1 cc = 1 mL = 0.001 liters
- 1 cc of water = 1 mL of water = 1 gram (at standard conditions)
- 1 cc = approximately 0.0338 US fluid ounces
- 1 US teaspoon = approximately 4.929 cc (or 4.929 mL)
Conversion Table
| Cubic Centimeters (cc) | Milliliters (mL) |
|---|---|
| 0.1 cc | 0.1 mL |
| 0.25 cc | 0.25 mL |
| 0.5 cc | 0.5 mL |
| 1 cc | 1 mL |
| 2 cc | 2 mL |
| 3 cc | 3 mL |
| 5 cc | 5 mL |
| 10 cc | 10 mL |
| 15 cc | 15 mL |
| 20 cc | 20 mL |
| 25 cc | 25 mL |
| 50 cc | 50 mL |
| 75 cc | 75 mL |
| 100 cc | 100 mL |
| 150 cc | 150 mL |
| 200 cc | 200 mL |
| 250 cc | 250 mL |
| 500 cc | 500 mL |
| 750 cc | 750 mL |
| 1000 cc | 1000 mL |
Recent Cases
Facts
- 1 cc and 1 mL are exactly the same volume by official SI definition since 1964.
- The abbreviation "cc" stands for cubic centimeter, also written as cm³.
- Medical syringes are commonly labeled in cc, though mL is increasingly preferred.
- A typical motorcycle engine ranges from 50 cc (scooter) to over 2000 cc (touring bike).
- 1 cc of water weighs exactly 1 gram at standard temperature and pressure.
Frequently Asked Questions
Yes. A cubic centimeter (cc) and a milliliter (mL) are exactly the same volume. 1 cc = 1 mL, always. The two terms are interchangeable. The difference is purely in naming convention: cc is preferred in medical and automotive contexts, while mL is the standard SI unit used in science and cooking.
Historically, the medical field adopted cc (cubic centimeter) before mL became the international standard. Many syringes, IV bags, and medical records still use cc out of tradition. However, modern medical guidelines increasingly recommend using mL to align with SI standards and reduce confusion.
A cubic centimeter (cc or cm3) is the volume of a cube that measures exactly 1 centimeter on each side. It equals one-millionth of a cubic meter. By definition, 1 cc is identical to 1 mL, making the two units perfectly interchangeable for all practical purposes.
In engines, cc refers to the total displacement volume of all cylinders combined. A 600cc motorcycle engine has cylinders with a total internal volume of 600 cubic centimeters (or 600 mL, or 0.6 liters). Higher cc generally means a larger, more powerful engine.
Yes. Since 1 cc equals 1 mL, and water has a density of 1 g/mL at standard conditions, 1 cc of water weighs exactly 1 gram. This convenient relationship is by design — the gram was originally defined as the mass of 1 cc of water at 4 degrees Celsius.