What is the USP size of a 3 metric suture?

• A. 3-0
• B. 1-0
• C. 4-0
• D. 2-0

Answer: (D)

Suture sizing uses two systems—USP and metric—and they’re not identical, so you use a cross-reference to map one to the other. A three metric suture is commonly matched to USP size 2-0 in standard reference tables, so the closest equivalent diameter is 2-0. This is why 2-0 is the best pick: it reflects the approximate thickness of a three metric strand in practical use.

The other options represent different cross-reference points: a smaller magnitude like 3-0 would be finer than 2-0, a larger magnitude like 4-0 would be even finer, and 1-0 would be thicker than 2-0. None of those align with the 3 metric sizing as used in typical references.