Free Online Compound Interest Calculator
Wondering how your money grows over time? Use this free, fast, and easy compound interest calculator to see how your investments grow with the power of compounding. Choose your currency, interest rate, time period, and compounding frequency to get instant results.
Advanced Compound Interest Calculator
Future value:
Total interest:
Rate of return:
Doubling time:
Pro Tip: Small Changes → Big Impact
Even a 1% increase in your interest rate or a ₹1,000/month extra deposit can dramatically change your financial future. Use the calculator to try different scenarios and see what works best for your goals.
What is compound interest and how does it work?
Compound interest is the magic of earning interest on your interest. When you invest money, you earn interest. But with compounding, that interest also earns interest. Over time, your money snowballs — the longer you leave it untouched, the more it grows.
How do I calculate compound interest manually?
To calculate compound interest manually, you’ll need this formula:
A = P × (1 + r/n)ⁿᵗ
Where:
t = number of years
But honestly, who has time to crunch all that? That’s why we built this calculator to do the heavy lifting for you instantly.
P = principal
r = annual interest rate (in decimal)
n = times interest is compounded per year
What’s the difference between simple and compound interest?
Simple interest only grows based on your original investment. Compound interest grows based on both your original amount and all the interest you’ve earned so far. Over time, compound interest earns you a lot more — it’s like giving your money a little superpower.
How often should interest be compounded for maximum growth?
The more often your interest is compounded, the faster your money grows. Daily compounding yields the most, followed by monthly, quarterly, and yearly. Even a slight change in compounding frequency can make a big difference over 10–20 years.
Can I add monthly deposits in the compound interest calculation?
Yes! Our calculator lets you add regular deposits — monthly, quarterly, or annually. You can even choose if the deposits happen at the beginning or end of each period, and apply an annual increase to simulate salary hikes or savings upgrades.
How does this calculator handle different currencies?
Simply choose your preferred currency — like USD, INR, EUR, GBP, or JPY — and the calculator updates the display instantly. All calculations work the same; the currency selection is for user clarity and international convenience.
How much will ₹1 lakh grow in 20 years at 8% interest?
With annual compounding and no extra deposits, ₹1 lakh at 8% would grow to around ₹4.66 lakh in 20 years. But if you add ₹5,000 monthly, it could reach over ₹30 lakh! Try different numbers in our calculator to see what works for you.
What is the Rule of 72 and how does it apply here?
The Rule of 72 is a quick way to estimate how long it takes for your money to double. Divide 72 by your interest rate. For example, at 8% interest, your money will double in about 9 years. Our calculator figures this out automatically for you.
Can I use this calculator for SIP or retirement planning?
Absolutely! Whether you’re investing monthly in mutual funds (SIP) or saving for retirement, this calculator helps you project your future wealth. Use it to test different contribution levels, interest rates, and timelines.
Is this compound interest calculator free to use?
Yes, 100% free. No sign-ups, no hidden fees. Just type in your values, hit “Calculate,” and get instant results. We believe financial tools should be accessible to everyone — no strings attached.