G (generation time) = (time, in minutes or hours)/n(number of generations)

G = t/n

t = time interval in hours or minutes

B = number of bacteria at the beginning of a time interval

b = number of bacteria at the end of the time interval

n = number of generations (number of times the cell population doubles during the time interval)

b = B x 2n (This equation is an expression of growth by binary fission)

Solve for n:
logb = logB + nlog2

n = logb - logB
   --------------
        log2

n = logb - logB
   -------------
       .301

n = 3.3 logb/B

G = t/n

Solve for G
G =       t
     -----------
     3.3 log b/B