Growth rate of odd size object:

Start: 1.5" w by 1.5" l by .25" h
End: 3.25" w by 3.50" l by .25" h
Did this object increase by 600%?

Some people tell me approx. 500% and 405%
Which is it and how do you do the math for the correct answer?

V1 = 1.5 *1.5 * 0.25 = 0.5625 in^3.

V2 = 3.25 * 3.50 * 0.25 = 2.844 in^3.

V2/V1 = 2.844/0.5625 = 5.056 = 505.6%.

% Increase = 505.6% - 100% = 405.6 %.