This is my first year not having earned income. I don't really understand how FireCalc can use my total investment accounts taxable and tax free to determine how much I can take each year. Is there something in the program that handles the taxes part? Also taxes for social security. I probobly didn't study the info thoroughly enough but the calculation said I would have 87% chance. Is it suggested that we try for 100%? Is starting at age 75 as accurate as starting at an earlier age.