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Compound Interest Calculator

Enter your starting principal, annual rate, term, and monthly contribution to estimate the future value, total contributions, and total interest. Switch between monthly and yearly compounding and view a year-by-year breakdown.

Input

Estimate the future value and total interest of compound growth from your principal, annual rate, term, and monthly contribution. This is a guide that assumes a constant rate of return.

$
$
%
yr

Compounding frequency

Result

Future value

$15,043,650

Total invested

$8,200,000

Total contributions

$7,200,000

Total interest

$6,843,650


Year-by-year breakdown

YearPrincipalInterestBalance
Year 1$1,360,000$59,528$1,419,528
Year 2$1,720,000$140,519$1,860,519
Year 3$2,080,000$244,072$2,324,072
Year 4$2,440,000$371,342$2,811,342
Year 5$2,800,000$523,541$3,323,541
Year 6$3,160,000$701,946$3,861,946
Year 7$3,520,000$907,896$4,427,896
Year 8$3,880,000$1,142,801$5,022,801
Year 9$4,240,000$1,408,143$5,648,143
Year 10$4,600,000$1,705,478$6,305,478
Year 11$4,960,000$2,036,444$6,996,444
Year 12$5,320,000$2,402,761$7,722,761
Year 13$5,680,000$2,806,238$8,486,238
Year 14$6,040,000$3,248,775$9,288,775
Year 15$6,400,000$3,732,372$10,132,372
Year 16$6,760,000$4,259,129$11,019,129
Year 17$7,120,000$4,831,255$11,951,255
Year 18$7,480,000$5,451,069$12,931,069
Year 19$7,840,000$6,121,013$13,961,013
Year 20$8,200,000$6,843,650$15,043,650

How it works

  • Enter your initial principal, annual interest rate, investment term, and monthly contribution to estimate the future value of compound growth, along with the total amount invested and total interest earned. This is a rough estimate that assumes a constant rate of return.
  • With monthly compounding, the annual rate is divided by 12 and applied to the balance each month, and your contribution is added at the end of each month (end-of-period contributions earn no interest in the month they are added).
  • With yearly compounding, the annual rate is applied once per year and twelve months of contributions are added at the end of each year. The more frequently interest compounds, the slightly larger the final balance for the same inputs.
  • Total invested is your initial principal plus all contributions; total interest is the future value minus the total invested. The year-by-year table shows the cumulative principal, cumulative interest, and balance at the end of each year.
  • Real-world returns vary and can be negative, so your principal is not guaranteed. This tool does not account for taxes on gains, fees, or inflation. Use it as a guide only and make investment decisions at your own risk.