# How do I calculate monthly compound interest with additional monthly deposits in Google Sheets?

I'm trying to figure out how to write a formula and/or use a function to calculate the following in Google Sheets.

John deposits \$1,000.00 into a savings account on Dec 31st. John also deposits \$100 on the 1st of every month and will do so for the next 10 years. The interest rate is fixed @ 4% for 10 years and compounds monthly. How much will John have after ten years?

``````\$1,0000 principal.
\$1,200 per year for 10 years.
Total deposits \$13,000.
``````

I currently have everything figured out with the exception of the monthly contribution. Screenshot of the data is below. How would I update to include the monthly \$100 contribution? Thanks for your help!

``````=C6*(1+C7/C9)^(C9*C8)
``````

This solution worked, `=fv(C7/C9,C8*C9,-C10)+C6*power(1+C7/C9,C8*C9)`

Final value would be `=FV(C7/C9,C8*C9,-C10)+C6*power(1+C7,C8)` or \$16,205.22
• Found it, `=fv(C7/C9,C8*C9,-C10)+C6*power(1+C7/C9,C8*C9)`. Needed to update the 2nd formula to include monthly compounding). Oct 22, 2022 at 0:30