Methodology
How the Compound Interest Calculator works
How Tallivo projects investment growth with compounding and recurring contributions.
The formula
FV = P(1 + r/12)^(12t) + PMT · [ ((1 + r/12)^(12t) − 1) / (r/12) ]
Step by step
- The annual return rate is divided by 12 and applied to the balance each month.
- Contributions are added at the end of each period (an ordinary annuity), then the next month's growth is applied to the new balance.
- Future value = your compounded starting amount plus the future value of the contribution stream.
- Total growth = future value − everything you contributed (principal + all contributions).
Assumptions & limitations
- A constant annual return — real markets fluctuate and can lose money.
- Nominal, pre-tax figures; taxes and inflation are not deducted.
- Monthly compounding regardless of the contribution frequency you pick.
Sources
Formula reviewed 2025. Figures are planning estimates, not a loan offer — this is not financial advice.