Compound Interest Calculator
Estimate the future value of an investment with compounding interest and optional regular contributions.
How is this result calculated?
Without contributions, the final balance follows the formula FV = P × (1 + r/n)^(n×t), where P is the initial capital, r the annual rate, n the number of compounding periods per year, and t the duration in years.
When a periodic contribution is added, the future value of the contributions is added to the previous result. The chart distinguishes, for each year, the capital actually contributed from the interest generated.
Frequently asked questions
What is compound interest?+
It's the fact that interest earned in one year is added to the capital and itself generates interest in the following years, unlike simple interest, which is calculated only on the initial capital.
What happens if the interest rate is 0%?+
No interest is generated: the final balance simply equals the initial capital plus the cumulative periodic contributions.
Annual vs. monthly compounding: what's the difference?+
With monthly compounding, interest is calculated and added to the capital 12 times a year instead of once: for the same displayed rate, the final balance is slightly higher.
How is the monthly contribution accounted for?+
The amount entered is a contribution per month. It is spread across the chosen compounding periods so that the total contributed over a year always equals this amount multiplied by 12.
Does this simulator account for inflation or taxes?+
No. It calculates a gross projection based on the compound interest formula, without taxes or inflation, which vary depending on the savings product and your situation.