What is the total cost of renting over 30 years, excluding insurance? To calculate the total rental cost over 30 years, excluding insurance, use the following formula: Total Rent=Rent_initial×(((1+r)^n−1)/(r))×12 Where: - Rent_initial is the initial monthly rent. - r is the annual rent increase rate (in decimal form, e.g., 3% = 0.03). - n is the number of years (in this case, 30).