Sam Z. answered 11/09/19
Math/Science Tutor
Monthly investments: If you make regular deposits to your account at the end of each month instead of a single lump-sum deposit, you need to modify your calculation or your spreadsheet formula.
If you deposit $100 per month for the next five years, starting from zero, you could use:
Interest on a series of investments:
=FV(0.004167,60,100)
Note that you use a monthly interest rate, and you adjust the number of periods to 60 months.
To calculate by hand, use the future value of an annuity calculation:
Example of a series of investments:
- FV = Pmt x (((1 + r) ^ n) – 1)/r)
- FV = 100 x (((1 + 0.004167) ^ 60) – 1) / 0.004167)
- FV = 100 x (1.283 – 1) / 0.004167
- FV = 100 x 68.0067
- FV = 6800.67