Long-tail calculator page

Compound Interest With Monthly Contributions

If you save or invest every month, you need more than the basic lump-sum formula. This page shows what to focus on and links straight to the main calculator configured for recurring deposits.

Best setup: open the main compound interest calculator, enter your starting amount, annual rate, years, and monthly contribution, then compare end-of-period versus beginning-of-period deposits.

What changes when you contribute monthly?

  • Your ending balance comes from both growth and new deposits.
  • Time still matters more than tiny differences in frequency.
  • Contributing earlier in each period usually produces a slightly higher outcome.

Illustrative example

Starting amountMonthly contributionRateYearsEstimated ending balance
$5,000$3007%20About $174,000

Best next step

Run your own numbers in the full calculator instead of relying on a generic chart. Real scenarios depend heavily on how long you keep contributing and whether the deposits happen at the beginning or end of each period.