- Principal
- Interest
- Total interest
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- Total amount
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Figures are estimates for planning only, not investment or tax advice.
Compound interest pays a return on your returns. This calculator applies it at whatever frequency you choose — yearly, half-yearly, quarterly or monthly — and shows the interest separately from the principal.
The formula
A = P × (1 + r/n)n×t. The more often interest is compounded, the more you end up with: ₹1,00,000 at 8% for 10 years produces ₹2,15,892 yearly and ₹2,21,964 monthly.
The rule of 72
Divide 72 by the annual rate to estimate how long money takes to double. At 8% that is 9 years, at 12% it is 6 years, at 6% it is 12 years. It is accurate enough for mental arithmetic anywhere in the 4–15% range.
Frequently asked questions
What is the difference between nominal and effective rate?
The effective rate accounts for compounding frequency. 12% compounded monthly has an effective annual rate of 12.68%.
Does compounding help borrowers?
No — it works against you on any debt where unpaid interest is added to the balance, credit cards above all.
How do I add monthly contributions?
Use the SIP calculator, which compounds a stream of monthly payments.