Specific Growth rate calculation
SGR  =  (lnWf - lnWi  x100) / t

Where :

lnWf = the natural logarithm of the final weight
lnWi = the natural logarithm of the initial weight
t = time (days) between lnWf and lnWi

If the Food Conversion Rate is known, the SGR can also be calculated by dividing the Percentage body weight fed per day by the food conversion rate.

This calculation can be turned round to predict growth if  the SGR is known