๐ Compound Interest Calculator
Enter your principal, monthly contribution, annual rate, and time horizon to simulate future value and total interest earned. Useful for visualizing how NISA or other regular investment plans can grow.
How to use
- Enter the principal (starting lump sum, if any).
- Enter the monthly contribution amount.
- Enter the expected annual rate and the number of years.
- Total contributions, total interest earned, and future value are calculated automatically.
FAQ
How often is compounding calculated?
Monthly contributions and interest are compounded monthly, accumulating to a projected future value over the full period.
Does this guarantee investment returns?
No. This is only a projection assuming the entered rate holds steady โ it does not guarantee actual investment performance.
Can I simulate contributions only, with no starting principal?
Yes โ leave the principal at 0 and enter only a monthly contribution to simulate a pure dollar-cost-averaging plan.
Does this account for NISA or iDeCo tax advantages?
No. This tool only performs a compound interest projection and doesn't model NISA or iDeCo tax-free allowances. For a plan more specifically modeled on NISA, see the NISA / DCA Investment Simulator.
How many years does it take to really feel the effect of compounding?
Compounding tends to accelerate the longer the period runs. Try comparing the future value at 10 years versus 20 years to get a feel for how much time itself matters.