As I am new to MTT and a foreigner scholar in China, have to really strive the language barrier over here.... so am writting down my question here, I do know the protocol for MTT but could not find any help form internet that how to further calculate/interpret my readings for MTT I got on excel.
Can somebody please guide me that after getting the data (absorbance reading) on microsoft excel how can I actually calculate the cell viability rate. I mean what will be the formula applied or what i have to do....no nothing

Assay was performed in six replicates for blank, control and each concentration of drug.
I used a blank (no cell only mtt reagent+DMSO), control (cells+mtt reagent+DMSO), and various concentration of my drug in micromole (from 1um to 100um). Now I don't know what to do further with the absorbance obtained. I shall be thankful to the one who can teach me step by step calculations for mtt on excel to get the final results (i.e percentage survival).