💰 Compound Interest Calculator

Calculate your investment growth with real-time updates and detailed visualizations

🏠 Also try our Mortgage Calculator

Investment Details

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Advanced Options

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Investment Summary

Future Value
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Total amount after time period
Total Interest
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Interest earned over time
Effective Annual Rate ℹ️
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True annual return (accounts for compounding)
Return on Investment
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Percentage gain

💡 Planning to buy a home? Use our Mortgage Calculator to see how much house you can afford and calculate your monthly payments. Perfect for planning your down payment savings!

Growth Chart ▼

Investment Overview ▼

Initial Investment $0
Compounding Frequency -
Time Period -
Number of Compounds 0

Investment Details

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Regular Contributions

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Investment Summary

Future Value
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Total amount after contributions
Total Contributions
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Amount you invested
Total Interest
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Interest earned
Interest as % of Total
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Growth from compounding

Growth Chart ▼

Contribution Breakdown ▼

Goal Details

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Current Savings

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Goal Analysis

Required Monthly Contribution
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To reach your goal
Total Contributions Needed
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Over time period
Interest Will Generate
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Projected Future Value
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Goal Progress Chart ▼

Compare Investment Scenarios

Compound Interest Resources & Guides

Learn about compound interest, understand key concepts, and get tips to maximize your investment growth.

📊 How to Use This Calculator

Our compound interest calculator is designed to be simple and powerful. Here's how to get the most out of it:

  • Basic Calculator: Enter your initial investment, interest rate, compounding frequency, and time period to see future value
  • With Contributions: Add regular contributions to see how consistent investing accelerates growth
  • Goal Calculator: Set a target amount and see how much you need to save monthly to reach it
  • Compare Scenarios: Compare different investment strategies side-by-side

All calculations update in real-time, and you can export results as PDF or CSV for your records.

📖 Understanding Compound Interest

💡 Related: Planning to buy a home? Use our Mortgage Calculator to see how much house you can afford and calculate your monthly payments.

Compound Interest: Interest calculated on the initial principal plus accumulated interest from previous periods. This creates exponential growth over time.
Compounding Frequency: How often interest is calculated and added. More frequent compounding (daily vs. annually) results in higher returns.
Effective Annual Rate (EAR): The true annual return when compounding is considered. Higher than the stated rate when compounding more than once per year.
Future Value: The amount your investment will be worth at a future date, including all interest earned.
Rule of 72: A quick way to estimate how long it takes to double your money: divide 72 by your interest rate. Example: 7% rate = ~10 years to double.

💡 Maximizing Compound Interest

  1. Start Early: Time is your greatest asset. Starting 10 years earlier can double or triple your final amount.
  2. Make Regular Contributions: Consistent monthly or yearly contributions dramatically increase your final balance.
  3. Choose Higher Rates: Even a 1% difference in interest rate can mean tens of thousands more over decades.
  4. Increase Compounding Frequency: Monthly compounding beats annual compounding, and daily is even better.
  5. Reinvest Dividends: Don't withdraw interest—let it compound to maximize growth.
  6. Stay Invested: Avoid withdrawing early. The power of compound interest increases exponentially over time.

❓ Common Questions

Q: How does compound interest differ from simple interest?

A: Simple interest is calculated only on the principal. Compound interest is calculated on principal plus previously earned interest, leading to exponential growth.

Q: Does compounding frequency really matter?

A: Yes! More frequent compounding means more growth. For example, $10,000 at 7% for 10 years: annually = $19,672, monthly = $20,096, daily = $20,137.

Q: How much should I contribute monthly?

A: Use our Goal Calculator to determine how much you need to save monthly to reach your target. Generally, aim to save 15-20% of income for retirement.

Q: What's a good interest rate for savings?

A: High-yield savings accounts offer 4-5%. Investment accounts (stocks, bonds) historically average 7-10% annually, but with more risk.

Frequently Asked Questions

Find answers to common questions about compound interest, calculations, and using our calculator tools.

Basic Calculator Questions

Compound interest is interest calculated on both your initial investment (principal) and the interest that has already been earned. This creates exponential growth because you earn interest on interest.

Example: If you invest $10,000 at 7% annually, after year 1 you have $10,700. In year 2, you earn 7% on $10,700 (not just $10,000), giving you $11,449. Over time, this compounding effect accelerates dramatically.

The formula is: A = P(1 + r/n)^(nt) where A = future value, P = principal, r = annual rate, n = compounding frequency, t = time in years.

Compounding frequency determines how often interest is calculated and added to your balance:

  • Annually: Interest calculated once per year
  • Quarterly: Interest calculated 4 times per year
  • Monthly: Interest calculated 12 times per year
  • Daily: Interest calculated 365 times per year

More frequent compounding = more growth. For example, $10,000 at 7% for 10 years: Annual = $19,672, Monthly = $20,096, Daily = $20,137.

The Effective Annual Rate (EAR) is the true annual return you receive when compounding frequency is considered. It's always equal to or higher than the stated annual rate.

Example: A 7% annual rate with monthly compounding has an EAR of 7.23%. This means you're effectively earning 7.23% per year, not just 7%.

EAR = (1 + r/n)^n - 1, where r = annual rate and n = compounding frequency.

Contributions Calculator Questions

Regular contributions dramatically accelerate your investment growth. Here's why:

  • Each contribution starts earning compound interest immediately
  • More money invested = more interest earned
  • Consistent investing takes advantage of dollar-cost averaging

Example: $10,000 initial + $500/month at 7% for 30 years = $656,000. Without contributions, you'd only have $76,123. Contributions added $180,000 but generated $465,877 in interest!

Contributing at the beginning of each period gives you slightly more growth because your money starts earning interest immediately. The difference is small but adds up over decades.

Example: $500/month at 7% for 30 years: Beginning = $656,000, End = $651,000. That's a $5,000 difference from timing alone.

Goal Calculator Questions

Use our Goal Calculator! Simply enter:

  • Your target amount (e.g., $100,000)
  • Time to reach goal (e.g., 20 years)
  • Expected interest rate (e.g., 7%)
  • Any initial savings you already have

The calculator will tell you exactly how much you need to save monthly to reach your goal. It accounts for compound interest, so you'll need to save less than if you were just dividing the goal by months.

Compound Interest Blog

Expert guides, tips, and insights to help you maximize your investment growth.

Complete Guide to Compound Interest: How It Works and How to Maximize It

Published: January 2026 | 6 min read

Learn everything about compound interest: how it works, why it's powerful, and how to use it to build wealth. This comprehensive guide covers the formula, real-world examples, and strategies to maximize your returns.

Key Topics: Compound interest formula, compounding frequency, Rule of 72, time value of money, investment strategies

Read More →

How Regular Contributions Can Turn $500/Month Into $1 Million

Published: January 2026 | 5 min read

Discover the power of consistent investing. See how regular monthly contributions, combined with compound interest, can help you build substantial wealth over time. Real examples and calculations included.

Key Topics: Dollar-cost averaging, regular contributions, compound interest with deposits, retirement planning

Read More →