MoneyBasisUnderstand your result
Future value
The estimated ending balance after contributions and compound growth over the period you entered.
Total contributed
Starting balance plus every recurring contribution made during the investment period.
Interest earned
The difference between future value and total contributed. This is an estimate, not a guaranteed return.
How this calculation works
- Enter a starting balance, recurring contribution, annual return and investment period.
- The calculator compounds monthly so contributions and growth stay on the same calendar.
- Compare the ending balance with the amount you contributed to see estimated growth.
FV = PV × (1 + r)^n + PMT × ((1 + r)^n − 1) / r
Future value uses monthly deposits and the monthly growth equivalent of the selected compounding frequency. PV is the starting balance, PMT is the monthly contribution, r is the monthly return, and n is the number of months. The annual return is a user-adjustable assumption, not a predicted market result.
- Compound interest
- Compound interest is growth calculated on both the original amount and accumulated growth from previous periods.
Assumptions & limitations
- Returns are a user-adjustable assumption. The default is not a historical guarantee or a forecast.
- The input is a nominal annual return. For frequency k, monthly return is (1 + annual rate/k)^(k/12) − 1.
- Contributions are made at the end of each month.
- Taxes and fees are excluded. The optional inflation-adjusted value expresses purchasing power separately.
Educational estimates only. MoneyBasis does not provide financial, investment, tax or legal advice.
Frequently asked questions
Does the result include my starting amount?
Can I compare different return assumptions?
How often does this calculator compound?
See a worked example
Saving & Investing · 5 min read
Compound Interest: Growth, Contributions and Inflation
Understand what you put in, what the model adds and what future dollars can buy.
Read guide →20 years · $10,000 + $500/month · 7% nominal, compounded monthly
- Contributed
- $130,000
- Modeled growth
- $170,851
- Future balance
- $300,851
Separate the money you add from the growth you assume.
Saving & Investing · 5 min read
Nominal vs Real Return: What Future Dollars Can Buy
A larger dollar balance does not always mean more purchasing power.
Read guide →$10,000 over 10 years · 7% annual growth · 3% inflation
- Future dollars
- $19,672
- Today’s buying power
- $14,637
One future balance, viewed in two different dollar units.
Saving & Investing · 5 min read
APR vs APY vs Investment Return
Match the rate definition to the calculator field before entering a percentage.
Read guide →Illustrative rates · separate examples
- APR
- 6.5%
- APY
- 5.00%
- Investment return
- 7.00%
Same “%” symbol. Different meaning.