Calculateur d'intérêts

Calculate simple or compound interest and see how your money grows over time. Get instant results with charts and year-by-year breakdown.

Vos coordonnées

$
%

Enter your principal, interest rate, and time period. Choose simple or compound interest, then click Calculate to see your results with charts and yearly breakdown.

Guide d'utilisation complet

What is Simple vs Compound Interest?

Simple interest is calculated only on the principal. Compound interest is calculated on the principal plus accumulated interest. Compound interest grows faster because you earn "interest on interest."

Simple: I = P × r × t

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

What Your Results Mean

Montant final

The total value at the end of the period: principal plus interest earned.

Intérêts gagnés

The total interest over the period. For compound interest, this includes interest on interest.

Taux effectif

For simple interest, this equals the stated rate. For compound interest, it reflects the actual annual return after compounding.

Comment utiliser cette calculatrice

  1. Enter your principal (starting) amount
  2. Enter the annual interest rate and time period (years, months, or days)
  3. Choose simple or compound interest
  4. For compound interest, select compounding frequency (monthly, daily, etc.)
  5. Click Calculate to see results, comparison, and yearly breakdown

Comprendre vos résultats

Principal vs Interest Chart

Shows how much of your final amount is principal versus interest earned.

Croissance équilibrée

Line chart of your balance over time. Steeper curve with compound interest.

Rule of 72

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

Formules utilisées

Simple interest:

I = P × r × t   |   A = P + I

Compound interest:

A = P(1 + r/n)^(n×t)

n = compoundings per year, t = time in years

Remarques importantes

  • This calculator is for educational and informational purposes only. It is not a substitute for professional financial advice.
  • Results are projections. Actual returns vary. Past performance does not guarantee future results.

When Simple Interest Applies

Some loans (e.g. short-term personal loans) use simple interest. You pay interest only on the principal, not on accrued interest.

When Compound Interest Applies

Savings accounts, CDs, and most investments compound. More frequent compounding (e.g. daily) yields slightly higher returns.

Conseils d'intérêt

  • Pour économiser, recherchez des comptes avec une capitalisation quotidienne pour maximiser les rendements.
  • La règle de 72 : divisez 72 par votre taux d’intérêt pour estimer les années à doubler.
  • Start saving early — time is the most powerful factor in compound growth.
  • For loans, prefer simple interest when available to pay less over time.

📤 Share This Tool