The primary result is explicitly U.S. fluid ounces. One cubic centimeter equals one milliliter. Using 1 U.S. gallon = 231 in³, 1 in = exactly 25.4 mm, and 128 U.S. fluid ounces per gallon gives:
Thus 100 cc is about 3.3814 US fl oz. The comparison row uses 28.4130625 cc per imperial fluid ounce and is labeled separately. Do not use a mass ounce in this volume conversion. Nonnegative valid numeric inputs are accepted; any result too large to represent is rejected.
Related volume converters: the ml to oz converter, the oz to cc converter, and the cc to ml converter.
Choose the fluid-ounce system before comparing containers
Use the US fluid-ounce output when comparing with a US volume label and the Imperial output for an Imperial label. Keep cc as the common input when checking both. Neither output is weight in ounces; a container’s volume and the mass of its contents are separate questions.
Three labels that must stay distinct
| Label | Quantity in this task | Appropriate comparison |
|---|---|---|
| cc or cm³ | Starting volume | Another volume of the same contents |
| US fl oz | The US fluid-ounce output | A label explicitly using that volume convention |
| Imperial fl oz | The separate Imperial output | A label using the Imperial convention |
A weight-oz measurement is outside this table. To connect mass and volume you need the material’s density, not a choice between the two fluid-ounce outputs.
Sources
- NIST, Guide for the Use of the International System of Units (SP 811) — SI units and accepted conversion guidance.
- NIST, Handbook 44, Appendix C — U.S. customary volume and length relationships used for dimensional arithmetic.