Compound Interest Calculator

Discover the power of compound interest. See how your investments can grow exponentially over time with regular contributions and compounding.

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Investment Results

Future Value

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Total value after 0 years

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Money you invested

Interest Earned

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Power of compounding

Growth Visualization

Your Money Growing

Year-by-Year Growth

Year Contributions Interest Balance Growth

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Understanding Compound Interest

The Power of Time

Rule of 72: Divide 72 by your interest rate to estimate how long it takes to double your money.

Start Early: Investing $100/month at age 25 vs age 35 can result in hundreds of thousands more at retirement.

Regular Contributions: Consistent monthly investments outperform lump-sum investments over time.

Maximizing Returns

Higher Frequency: More frequent compounding (monthly vs annually) can significantly increase returns.

Tax-Advantaged Accounts: Use 401(k)s, IRAs, and other tax-advantaged accounts to maximize compound growth.

Dollar-Cost Averaging: Regular investments reduce the impact of market volatility on your portfolio.

Real-World Examples

Child's Education

$100/month at 7% for 18 years:

$21,600 invested

grows to $55,000+

House Down Payment

$300/month at 6% for 8 years:

$28,800 invested

becomes $42,000+

Retirement Fund

$250/month at 8% for 35 years:

$105,000 invested

grows to $500,000+

Investment Strategies & Tips

Long-Term Investing

Time Horizon: The longer your investment period, the more compound interest works in your favor.

Market Timing: Trying to time the market usually hurts returns. Stay invested through ups and downs.

Rebalancing: Periodically adjust your portfolio to maintain your desired risk level.

Emergency Fund: Keep 3-6 months of expenses in cash before investing aggressively.

Risk Management

Diversification: Don't put all eggs in one basket. Spread investments across asset classes.

Asset Allocation: Balance risk and reward based on your age and risk tolerance.

Regular Reviews: Monitor performance but avoid frequent trading that can hurt returns.

Inflation Protection: Consider assets that historically outpace inflation over time.

Compound Interest FAQ

What's the difference between simple and compound interest?

Simple interest is calculated only on the principal amount. Compound interest is calculated on both principal and accumulated interest from previous periods, leading to exponential growth.

How often should I check my investments?

For long-term investments, quarterly or annual reviews are usually sufficient. Daily checking can lead to emotional decision-making. Focus on your long-term goals rather than short-term fluctuations.

What are index funds and should I invest in them?

Index funds track market indices and have low fees. They're great for most investors since they historically outperform most actively managed funds over long periods due to lower costs and diversification.

How do taxes affect compound interest?

Taxes can significantly reduce compounding. Use tax-advantaged accounts like 401(k)s, IRAs, or Roth IRAs. Capital gains taxes apply when you sell investments that have appreciated in value.

Tax-Advantaged Investment Accounts

401(k)

Employer-sponsored retirement plan with tax advantages.

  • • Pre-tax contributions
  • • Employer matching possible
  • • $23,000 limit (2024)

Traditional IRA

Individual retirement account with tax deductions.

  • • Tax-deductible contributions
  • • Taxed upon withdrawal
  • • $7,000 limit (2024)

Roth IRA

After-tax contributions with tax-free growth.

  • • After-tax contributions
  • • Tax-free withdrawals
  • • Income limits apply

529 Plan

Education savings with tax advantages.

  • • Tax-free growth
  • • Tax-free withdrawals for education
  • • State tax benefits

HSA

Health savings account with triple tax benefits.

  • • Pre-tax contributions
  • • Tax-free growth
  • • Tax-free medical expenses

Brokerage Account

Taxable investment account with full flexibility.

  • • No contribution limits
  • • Capital gains taxes apply
  • • Full control over investments