How many inches are in a box 2.6 inches wide by 14inches long by 3inches high?

2.6 inches times 14 inches times 3 inches = 109.2 cubic inches. The solution is not in inches, but in cubic inches. If you are measuring it as carry-on or checked airline baggage, it is 3 + 14 + 3 = 20. The 2.6 inches counts as 3.