This is my current retirement plan:

Total expenses for 30 years of retirement I'm estimating: 67910000 Thai baht

Future value of expense at the time of retirement: 196822081 THB

My current savings is 0

Estimated average annual rate of return: 7.5%

Inflation Rate: 3%

Based on the annual expenses worked out above, calculate how much total savings i should have on the day you retire (i.e., the present value of all the expenses you need for retirement on the day i will stop working) using the rate of return assumed above. Next part based on the total savings required found and the current savings reported above, find out how much i need to save each year now until the day i will stop working, given an interest rate i have described in above. Please show workings. Also show what formula to use if done on excel.