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Simple interest calculator

Measure how much interest you can generate with your investments.

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Future investment value

20 000 €


10 000 €


20 years



After 20 years at a rate of 5%, you will obtain a future investment value of 20 000 €.

This tool is for information purposes only. It should not be considered as financial advice.

Understanding simple interest and its calculation

Simple interest is often used for short-term investments (less than one year).

For bonds, term accounts, and sometimes certain crowdfunding or crowdlending platforms, the calculation of interest can differ. Indeed, depending on the choice of investment, the interest will be simple or compounded.

What are the differences?

For simple interest, the sum of interest received is determined by the initial amount invested, regardless of the investment period. Whether the investment lasts 12, 24, or 36 months, the annual interest remains the same. This is because the interest is calculated exclusively on the initial principal amount and is distributed at the conclusion of each year.

Are you curious about how to calculate simple interest?

Let's first examine the basic formula for simple interest:

Vf = Vi × (1 + ρ/n)^(n×t)

The formula for simple interest, expressed by Vf = Vi + (Vi·ρ·ᵅ), shows the growth of an investment or loan over a given period.

Here's what each term represents:

  • Vf is the future value of your investment;
  • Vi indicates the initial value or principal amount;
  • ρ (rho) represents the annual interest rate, expressed as a percentage (for example, 5% would be 0.05);
  • denotes the number of years of the investment.

The major difference between compound interest and simple interest lies in the calculation of interest: simple interest is calculated only on the initial capital, without taking into account the interest accumulated in previous years.

Interpreting the results of the simple interest simulator

The simple interest simulator is a practical tool for understanding the growth of your short-term investments. You start by entering your initial capital, and then determine the expected annual interest rate of your investments.

The simulator calculates simple interest based on the initial capital and the interest rate, providing a clear view of the growth of your capital over a defined period. It's an ideal tool for planning short-term investments or understanding the impact of simple interest loans, such as certain types of credits or borrowings.

How to use the simple interest simulator

Once you have entered the necessary information, the simulator displays the future value of your capital, taking into account the principal amount and the interest accumulated over the chosen period.

A chart illustrating the evolution of your investment is also presented, highlighting how the initial capital, with the application of simple interest, evolves over time. This allows you to easily visualize the impact of your initial investment and your interest rate choices on the final value of your capital.

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