Which multiplicative factor is used in the graft flow volume equation to convert to per-minute units?

• A. 1
• B. 60
• C. 30
• D. 120

Answer: (B)

The main idea is converting flow rate from per second to per minute in the graft flow volume calculation. In practice, you multiply velocity by cross-sectional area to get volume flow per second, then multiply by 60 to convert to per-minute units, since there are 60 seconds in a minute. The standard form is Q = Vmean × A × 60, which yields flow in mL/min (since 1 cm^3 = 1 mL). Using 1 would give per-second flow, while 30 or 120 would incorrectly assume 30 seconds or 120 seconds per minute, respectively.