How the Compound Interest Calculator Works
Enter your principal amount, the annual interest rate, the time period, and how often interest compounds (yearly, half-yearly, quarterly or monthly).
Optionally add a monthly contribution to see how regular top-ups accelerate growth alongside your principal's compounding.
The calculator shows your interest earned, final amount, and overall growth percentage, along with a year-wise growth table.
Formula Used
The principal grows using the standard compound interest formula:
A = P × (1 + r/n)^(n×t)- AFinal amount
- PPrincipal
- rAnnual interest rate (as a decimal)
- nCompounding periods per year
- tTime period in years
Example Calculation
A simple example with yearly compounding and no additional contributions.
- Principal₹1,00,000
- Interest Rate8% p.a.
- Time Period10 years
- CompoundingYearly
- ResultFinal Amount ≈ ₹2,15,892 (Interest Earned ≈ ₹1,15,892)
Important Assumptions
- The interest rate is assumed to remain constant for the entire period — real-world rates on savings instruments and investments can vary over time.
- If you add a monthly contribution, it is projected using monthly compounding at the same annual rate, regardless of the compounding frequency chosen for the principal, since recurring monthly amounts are naturally modelled on a monthly basis.
- This calculator is for illustrative and educational purposes and does not account for taxes, fees, or charges that may apply to real investment or deposit products.