Our widest drawer bank is 30”. The line of pulls we are looking (Jeffrey Alexander Loxley) at come in the following (actual, not center to center) lengths:

5 7/8

7 1/8

8 3/8

12 13/16

Using the 1/3 rule, we would want a 10” pull so the 8 3/8 is the closest.

Would an 8 3/8 be too small? Going to nearly 13” seems too large. The largest pull is also 4x the cost of the next largest, oddly.