Iodine value calculation
Assuming you are given normality of sodium thiosulphate as 0.1 N (or sometimes called standard), you could use this formula to find the iodine value:

iodine number=$$\frac{(mL 0.1N Na_2S_2O_3 blank  – mL 0.1 N Na_2S_2O_3 test) (12.7)(100)}{(1000) (1.1)}$$


Where “mL 0.1 N Na2S2O3 Blank” = the volume of sodium thiosulphate required to titrate
the blank solution,
Where “mL 0.1 N Na2S2O3 Test” = the volume of sodium thiosulphate required to titrate the
test solution that contained either solid fat or oil as the sample,
Where “12.7” is the amount of grams of iodine contained in one litre of 0.1 N iodine,
Where “1.1” is the amount of fat taken in grams  and,
Where “100” converts the sample to per 100 grams of fat.