#Donations per annum

Isn't it time to calculate and let the individuals or Earners know the exact amount that can be allocated by them or given or distributed as donations to trust, place of worship, sports, local event's, Festival's and so on based on their annual income as per IT statements and mapped with their transaction taxes or taxes deducted or reduced from their annual incomes i.e (all earnings-all expenses -all taxes (livelihood))? 

This amount should not cross n%, where n is a factor of (annual earnings - all expenses -all taxes). The annual donations or n% can vary based on the transaction taxes slab to donate more based on your net savings per annum. This formula requires at least one year earnings or based on last years net savings information.  The contribution could range between n and m, where in n is the least value and m is the greatest value.

What do we think or say about this idea?