Written and maintained by CASRAI Editorial Board
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General unit information for supply and clinic staff. It is not medical advice and says nothing about how much of anything to give a person.
Short answer
1 cc equals 1 mL. “cc” stands for cubic centimeter, and one milliliter is exactly one cubic centimeter, so 3 cc is 3 mL and 60 cc is 60 mL. The practical point is the label: the Institute for Safe Medication Practices (ISMP) lists “cc” among error-prone abbreviations because it can be mistaken for “u” (units), and tells writers to use mL.
1 cc, 1 mL and cm³: three spellings of one volume
NIST’s Guide for the Use of the SI (SP 811) gives the liter as 1 L = 1 dm³ = 10⁻³ m³. A cubic decimeter is 1,000 cubic centimeters, so 1 L = 1,000 cm³, and a milliliter (one thousandth of a liter) is 1 cm³. That last step is arithmetic from the NIST relation, not a sentence NIST prints. NIST also states that, in the United States, the liter symbol to use is L.
| Written as | Means | Source for the reading |
|---|---|---|
| 1 cc | 1 cubic centimeter | ISMP error-prone abbreviation list (2024): “cc” is “cubic centimeters” |
| 1 cm³ | 1 cubic centimeter | Same unit, written with the SI exponent; derived from NIST SP 811 |
| 1 mL | One thousandth of a liter, equal to 1 cm³ | Derived from NIST SP 811, 1 L = 1 dm³ |
| 1 L | 1 dm³, which is 1,000 cm³ | NIST SP 811, Table 6 |
“1cc ml” and “1ml cc” are therefore the same statement in either order, not two different quantities. Both measure volume, not mass or weight.
3 cc, 60 cc and “1 mL/cc” syringe labels
3 cc to mL
3 cc is 3 mL. The conversion is one-to-one at every size, so there is no factor to apply.
60 cc to mL
60 cc is 60 mL, by the same one-to-one equality.
What “1 mL/cc” and “3 mL/cc” mean on a listing
Product listings often write a syringe size as “1 mL/cc” or “3 mL/cc”. Because the two units are equal, that notation says the same volume twice, once in each spelling. It tells you nothing about the tip, needle or other features. For tip styles see our guide to syringe tip types, and for the parts of the device see what a syringe is.
Why labels say mL: the ISMP finding
ISMP’s List of Error-Prone Abbreviations, Symbols, and Dose Designations (2024) has this row under abbreviations for doses and measurement units: cc, meaning cubic centimeters, with the hazard “mistaken as u (units)” and the instruction “use mL”. A handwritten or printed “cc” can look like “u”, and “u” for units is itself on the same list, with ISMP asking writers to spell out “unit(s)”. The fix ISMP gives is a unit that cannot be misread that way.
This is a labeling point, not a conversion problem. The two units are equal; the risk is in the characters on the page. For the wider picture of how errors arise, see our overview of types of medication errors.
Supply-desk check for “cc” and “mL” wording
The checklist below is an editorial working aid built on the two sourced points above (equal units; ISMP’s instruction to use mL). It is not a requirement from any standard.
- Read the unit printed on the barrel scale of the syringe actually on the shelf, not only the carton or catalog line.
- Write mL, never cc, on requisitions, par-level sheets and internal specification sheets.
- If a supplier listing gives only cc, convert it on your own record to the same number in mL (1 cc = 1 mL) and keep the supplier’s wording beside it so the line can still be matched.
- Treat “mL/cc” listings as a size statement only; confirm the tip type separately.
- Do not read a volume as a weight. A milliliter is a unit of volume, so a size in mL says nothing about how heavy the contents are.
- Keep sizing for specific products to the manufacturer’s own instructions and labeling. Insulin syringes have their own scale conventions, covered in our guide to insulin syringe sizing.
For stocking questions beyond units, see bulk syringes and whether syringes expire.
Common misunderstandings
- “cc and mL are slightly different.” They are the same volume. The difference is only how the unit is written.
- “cc is the metric unit and mL is not.” Both are metric; NIST’s relation 1 L = 1 dm³ ties the milliliter directly to the cubic centimeter.
- “A bigger cc number means a different unit.” 1 cc, 3 cc and 60 cc are all counted in the same unit, so the number alone sets the size.
- “cc is fine because everyone knows it.” ISMP lists it as error-prone for exactly that reason: familiarity does not stop it being misread as “u”.
FAQ
Is 1 cc the same as 1 mL?
Yes. 1 cubic centimeter equals 1 milliliter, which follows from NIST’s 1 L = 1 dm³.
What is 1ml cc?
It is the same quantity written in both units. 1 mL and 1 cc are equal.
How many mL is 3 cc?
3 mL. The same applies to 60 cc, which is 60 mL.
What does a “1 mL/cc syringe” mean?
It is a listing style that gives the size in both unit spellings. It describes volume only, not tip type or needle.
Why should I write mL instead of cc?
ISMP lists “cc” as an error-prone abbreviation that can be mistaken for “u” (units) and says to use mL.
Sources
- ISMP, List of Error-Prone Abbreviations, Symbols, and Dose Designations, 2024: online.ecri.org ISMP list (PDF). Checked 2026-11-01.
- NIST, Guide for the Use of the International System of Units (SI), Special Publication 811, Chapter 5, Units Outside the SI: nist.gov SP 811 chapter 5. Checked 2026-11-01.
