How does compound interest work?
Wondering how to calculate compound interest? Let's get straight to the point by breaking down the formula for annually compounded interest:
- Vf is the future value of the investment.
- Vi represents the initial value, or principal amount.
- ρ (rho) is the annual interest rate (expressed as a decimal, so a rate of 5% would be 0.05).
- n is the number of times interest is compounded per year.
- t is the number of years the money is invested or borrowed.
Compound interest differs from simple interest in that it calculates interest not only on the initial principal, but also on the interest accumulated over previous periods, leading to exponential growth of the invested capital over time.
How to use the compound interest calculator?
The compound interest calculator is an easy-to-use tool for visualizing the potential growth of your investments over the long term. To begin, enter your initial capital and the amount you plan to save each month.
Then choose your investment horizon, in years, and the annual interest rate you expect from your investments.
The calculator simulates compound interest based on your regular contributions and the interest rate, showing how your capital can grow over time. It factors in interest payments, which can be set to a monthly frequency, to give you an accurate estimate of the final capital you could accumulate.
It's the ideal tool for planning your long-term investments, whether in stock-market assets or other asset types such as real estate, cryptocurrencies or savings accounts. If you're looking for guidance on how much to invest, our budget calculator can help you build a realistic savings plan.
Understanding the compound interest calculator results
After filling in the various fields, you'll see on the right the final compound value of your initial capital, contributions & interest earned over the chosen period, along with the contribution frequency.
The chart below illustrates how your investment evolves over time, highlighting the significant impact of compound interest on your capital. You'll clearly see how your initial investments, combined with regular contributions and accumulated interest, work together to grow your overall wealth.
The compound interest formula, expressed as Vf = Vi × (1 + ρ/n)n×t, describes how an investment or loan grows over time.
