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Interest Calculator

Calculate simple and compound interest. See how your money grows over time.

Interest Calculator

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Results

Compound: A = P(1 + r/n)^(nt) (n = 12)

Principal

$10,000.00

Interest

+$1,614.72

Final Amount

$11,614.72

Year-by-Year

YearPrincipalInterestTotal
Year 1$10,000.00+$511.62$10,511.62
Year 2$10,000.00+$1,049.41$11,049.41
Year 3$10,000.00+$1,614.72$11,614.72

• Simple: Interest on principal only / Compound: Interest on interest

• More frequent compounding = higher returns

• Savings mode: Monthly deposits with compound interest

Note: Actual returns may vary due to taxes, fees, and market conditions.

💵 What is Interest Calculator?

Interest Calculator computes simple and compound interest along with maturity amounts using principal, rate, and time period. Use it for savings accounts, CDs, bonds, investments, and any financial planning that involves interest. The savings mode calculates compound interest with regular monthly deposits, while the compare mode helps find the best product. Goal calculator works backwards to find required principal, rate, or time to reach your target amount.

📊 Simple vs Compound Interest

AspectSimple InterestCompound Interest
CalculationInterest on principal onlyInterest on principal + interest
FormulaA = P(1 + rt)A = P(1 + r/n)^(nt)
Long-term GrowthLinear increaseExponential increase
Common UsesBond yields, short loansSavings, CDs, investments

💡 Interest Calculation Tips

  • Compounding frequency: Monthly > Quarterly > Yearly (more frequent = higher returns)
  • Tax consideration: Interest income is typically taxed (15% in this calculator)
  • Rule of 72: 72 ÷ annual rate = years to double money (e.g., 6% → 12 years)
  • Effective rate: APY (Annual Percentage Yield) accounts for compounding

Frequently Asked Questions

How much interest will I earn on $10,000 at 5%?

For a 1-year CD at 5% with monthly compounding, you would earn about $511.62 before taxes. After 15% tax, you receive approximately $434.88 in interest.

Why does compound interest grow faster?

Compound interest earns interest on your interest. Over time, this creates exponential growth as each period adds interest on an increasingly larger balance.

What is APY vs APR?

APR (Annual Percentage Rate) is the simple interest rate. APY (Annual Percentage Yield) includes the effect of compounding, making it higher. Always compare APYs for savings products.

What is Interest Calculator?

Calculate how much interest you will earn or owe. Compare simple vs compound interest and see how your money grows over time with different compounding frequencies.

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