The online mortgage loan calculator

After a few visits to the show unit for the newly launched housing area, Gary decided to get a unit for himself. He wanted to be sure that he can afford to pay the housing loan therefore he try to calculate how much he needs to pay per month by putting down the property price, down payments, interest rates and etc. When he showed it to me, I told him it seems that his calculation is not very correct. Why makes your life so difficult trying to figure out which formula is correct when you can use