Compound Interest Calculator
I've always said that compound interest is the eighth wonder of the world. I built this tool to help you visualize exactly how your money can work for you over time.
Calculator Inputs
Adjust the numbers to see how your wealth grows.
Estimated Results
Here's what your future looks like.
Compound Interest Calculator in 3 Simple Steps
I've made it incredibly easy for you to project your future wealth. Here's how I use this tool to plan my own investments.
1. Input Your Numbers
Start by entering your initial investment and how much you can contribute monthly. Be honest with yourself—even small amounts add up over time!
2. Set Your Growth Rate
Choose your expected interest rate and time horizon. I usually use 7-8% for long-term stock market projections to stay conservative.
3. Visualize Your Wealth
Hit calculate and watch the magic happen. I love seeing the "Total Interest Earned" section—it's the money your money made for you!
Why I'm Obsessed with Compound Interest
I'll be completely honest with you: when I first started my financial journey, I was focused on the wrong things. I was looking for "the next big stock" or trying to time the market perfectly. It wasn't until I sat down and really looked at the math of compound interest that my entire perspective shifted.
Compound interest isn't just a financial formula; it's a wealth-building superpower. It's the reason why a 20-year-old who saves a little can end up wealthier than a 40-year-old who saves a lot. It's about time, consistency, and letting the math do the heavy lifting for you.
The Formula I Use
Don't let the math scare you. A is your final amount, P is your starting principal, r is your interest rate, n is how often it compounds, and t is the number of years. My calculator handles all of this behind the scenes so you don't have to.
How I Beat the Competition (And How You Can Too)
Most compound interest calculators you'll find online are... well, boring. They give you a number and send you on your way. But I wanted to build something better. I wanted to show you the "Why" and the "How".
- ✓Start Early: I can't stress this enough. Every year you wait is a year of compounding you'll never get back.
- ✓Increase Frequency: Compounding monthly is better than annually. Compounding daily is even better. My calculator lets you see the difference.
- ✓Don't Touch the Principal: The magic only works if you let the snowball keep rolling. Resist the urge to withdraw!
My Secret Tip: The Rule of 72
Want to know how long it will take to double your money? Divide 72 by your interest rate. If you're earning 8%, your money will double in 9 years (72 / 8 = 9). I use this mental shortcut all the time to quickly evaluate investment opportunities.
Frequently Asked Questions
What is the best compounding frequency?
Generally, the more frequent the better. Daily compounding will yield more than annual compounding, though the difference becomes smaller as the frequency increases. For most people, monthly compounding is a great balance and is what most banks use.
Can I use this for my savings account?
Absolutely! Just enter your current balance as the initial investment and your bank's APY as the interest rate. It's a great way to see how your emergency fund grows.
How does inflation affect my results?
Inflation reduces the purchasing power of your future money. If you want to see your results in 'today's dollars', I recommend subtracting 2-3% from your expected interest rate.
Is compound interest better than simple interest?
Yes, 100%. Simple interest only pays you on your original principal. Compound interest pays you on your principal AND your accumulated interest. Over long periods, the difference is massive.
Ready to Build Your Empire?
The best time to start was 20 years ago. The second best time is right now. Use the calculator above and start your journey.
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