Compound Interest Calculator | Calculate Your Investment Growth
Input Your Data
Results
Initial Investment:
Total Contributions:
Total Interest:
Final Balance:
Compound Interest Calculator – See How Your Money Grows
Imagine putting $1,000 into a savings account and forgetting about it for 10 years. You expect it to grow a little, but when you check back, the balance is higher than you thought. Why? That’s the power of compound interest — your money earns interest, and then that interest earns interest too. A Compound Interest Calculator helps you visualize this growth, showing exactly how much you’ll have in the future, based on your investment, contributions, and compounding frequency.
Why Compound Interest Matters
Compound interest is often called the eighth wonder of the world because of how quickly wealth grows when you give it time. Here’s why it’s important:
- Saves for the future: See how your savings account or retirement fund could grow.
- Motivates consistent investing: Small monthly contributions make a big difference.
- Shows the power of time: The earlier you start, the bigger the results.
- Helps planning: Useful for retirement, college funds, or any long-term financial goal.
What You Need to Enter
The calculator works with a few simple inputs:
- Initial Investment ($): The starting amount you put in.
- Annual Interest Rate (%): How much your money grows per year, usually set by banks or investments.
- Time Period (Years): How long you plan to invest.
- Monthly Contribution ($): Optional – regular deposits boost growth.
- Compounding Frequency: How often interest is applied (annually, semi-annually, quarterly, monthly, or daily). More frequent compounding means faster growth.
What You Need to Enter
The calculator works with a few simple inputs:
- Initial Investment ($): The starting amount you put in.
- Annual Interest Rate (%): How much your money grows per year, usually set by banks or investments.
- Time Period (Years): How long you plan to invest.
- Monthly Contribution ($): Optional – regular deposits boost growth.
- Compounding Frequency: How often interest is applied (annually, semi-annually, quarterly, monthly, or daily). More frequent compounding means faster growth.
The Formula Behind Compound Interest
The general compound interest formula is:
A = P × (1 + r/n) ^ (n×t) + (C × ((1 + r/n) ^ (n×t) - 1) / (r/n))
Where:
- A = Final Balance
- P = Initial Investment
- r = Annual Interest Rate (decimal form)
- n = Compounding Frequency (times per year)
- t = Time in Years
- C = Monthly Contribution
This formula accounts for both your starting investment and regular contributions.
How the Calculator Works (Step by Step)
- Enter Your Initial Investment: This is your starting balance.
- Choose Interest Rate: Input the annual percentage your investment earns.
- Select Time Period: Enter how many years you’ll leave the money invested.
- Add Monthly Contributions (if any): This shows the benefit of regular deposits.
- Pick Compounding Frequency: Choose annual, quarterly, monthly, or daily compounding.
- Calculate: The tool applies the formula and shows:
- Initial Investment (your starting money)
- Total Contributions (all extra deposits made over time)
- Total Interest (how much your money earned)
- Final Balance (the total value of your investment)
- Initial Investment (your starting money)
Example Calculation
- Initial Investment: $5,000
- Interest Rate: 6%
- Time Period: 10 years
- Monthly Contribution: $100
- Compounding: Monthly
Results:
- Initial Investment: $5,000
- Total Contributions: $12,000
- Total Interest: $9,650 (approx.)
- Final Balance: $26,650
This shows how contributions + compounding work together to grow wealth.
