Compound Interest Calculator
Calculate compound interest online — with or without compounding frequency. Get real-time results for investments, FDs, and savings.
Calculation Mode
Formula
A = P × (1 + R/100)^T
Result
Total Amount
After 2 years
Compound Interest Calculator – Calculate CI Online
Our free compound interest calculator online helps you calculate CI for any investment, fixed deposit, or loan in India. Simply enter the principal amount, annual interest rate, time period, and compounding frequency — and get instant, accurate results. No signup. No complexity.
What is Compound Interest?
Compound Interest (CI) is interest calculated on both the initial principal and the interest accumulated from previous periods. Unlike simple interest — which only earns on the original amount — compound interest grows exponentially over time because each period's interest is added to the principal before the next period is calculated.
This "interest on interest" effect is what makes compound interest so powerful for long-term savings and investments. It is the basis of most fixed deposits, mutual funds, and savings accounts in India.
Compound Interest Formula
Basic Formula
- A — Total amount (principal + interest)
- P — Principal amount
- R — Annual interest rate (%)
- T — Time period in years
With Compounding Frequency
- n = 1 — Yearly compounding
- n = 2 — Half-yearly compounding
- n = 4 — Quarterly compounding
- n = 12 — Monthly compounding
Example Calculation
You invest ₹10,000 at 10% for 2 years, compounded yearly:
Year 1: A = 10,000 × (1 + 10/100)^1 = ₹11,000
Year 2: A = 11,000 × (1 + 10/100)^1 = ₹12,100
Total Amount = ₹12,100 · Interest Earned = ₹2,100
With simple interest at the same rate, you would only earn ₹2,000. Compound interest earns you an extra ₹100 — and this gap widens significantly over longer periods.
Simple Interest vs Compound Interest
Simple Interest
- Interest only on original principal
- Same amount earned every year
- Formula: SI = (P × R × T) ÷ 100
- Lower total return over time
- Used in: short-term loans, vehicle loans
Compound Interest
- Interest on principal + accumulated interest
- Grows faster every year
- Formula: A = P × (1 + R/100)^T
- Higher total return over time
- Used in: FDs, mutual funds, savings
Benefits of Compound Interest
Exponential Growth
Your money grows faster over time because each period's interest is reinvested. Small amounts can grow significantly over 10–20 years.
Rewarding Long-Term Investors
The longer you stay invested, the more powerful compounding becomes. Starting early — even with small amounts — makes a huge difference.
Higher Frequency = Higher Returns
Monthly compounding gives more returns than yearly compounding at the same rate, because interest is added more frequently.
Used Everywhere in India
Bank FDs, PPF, EPF, mutual funds, and most investment products in India use compound interest as the basis for calculating returns.