Calculateur d'intérêts composés

Calculate how your savings or investments grow over time with compound interest and regular contributions. Get instant results with growth charts and year-by-year breakdown.

Vos coordonnées

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Cotisations régulières (facultatif)

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Enter your initial investment, interest rate, time period, and optional contributions, then click Calculate to see your projected growth with charts and year-by-year breakdown.

Guide d'utilisation complet

What is Compound Interest?

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest, it grows your balance faster over time because you earn interest on interest.

A = P(1 + r/n)^(nt)

A = final amount, P = principal, r = annual rate, n = compoundings per year, t = years

The more frequently interest compounds (e.g. monthly vs annually), the more you earn. This calculator also supports regular contributions to show how saving consistently boosts growth.

What Your Results Mean

Solde final

The projected value of your investment at the end of the time period, including principal, contributions, and interest.

Intérêt total

The total interest earned over the period. This is the growth from compounding (and from contributions earning interest).

Fréquence composée

How often interest is added (annually, monthly, daily, etc.). More frequent compounding yields slightly higher returns.

Comment utiliser cette calculatrice

  1. Enter your initial investment (principal)
  2. Enter the annual interest rate and compound frequency
  3. Enter the time period in years
  4. Optionally add regular contribution amount, frequency, and timing (beginning or end of period)
  5. Cliquez sur « Calculer » pour voir vos résultats
  6. Review the summary cards, growth chart, breakdown charts, and year-by-year table

Comprendre vos résultats

Growth Chart

Shows total balance and total deposits over time. The gap between them represents interest earned.

Répartition du solde final

Pie chart of how much of your final balance came from initial investment, contributions, and interest.

Rule of 72

Divide 72 by your interest rate to estimate years to double your money. At 7%%, money doubles in about 10 years.

Formules utilisées

Compound amount without contributions:

A = P(1 + r/n)^(n×t)

With regular contributions, the calculator compounds each period and adds contributions at the chosen timing (beginning or end of period).

Remarques importantes

  • This calculator is for educational and informational purposes only. It is not a substitute for professional financial or investment advice.
  • Results are projections. Actual returns vary. Past performance does not guarantee future results.
  • For investment planning, consider consulting a financial advisor.

Impact of Starting Late

Waiting to invest can mean:

  • Less time for compounding
  • Need for larger contributions to catch up
  • Lower final balance for the same effort

Benefits of Compounding

Starting early and contributing regularly can:

  • Grow wealth with less stress
  • Let interest do more of the work
  • Build a larger nest egg over time

Conseils d'investissement

  • Start investing as early as possible; time is your biggest advantage.
  • De petites cotisations constantes peuvent surpasser de gros investissements ponctuels.
  • Reinvest dividends and interest to maximize compounding.
  • Keep fees low; even 1% in fees can significantly reduce long-term returns.

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