Savings and growth utility
Compound Interest Calculator
Model a lump sum, recurring contributions, compounding frequency, effective annual rate, and inflation-adjusted value.
Calculate compound growth
Formula
A = P × (1 + r ÷ n)n×t. Contributions are added at the selected interval and compound for their remaining time.
Examples
₹1,00,000 at 8% compounded monthly for 10 years grows to about ₹2.22 lakh without extra contributions. Adding ₹5,000 monthly materially changes the final value.
Frequently asked questions
What is the compound interest formula?
For a lump sum, A = P × (1 + r ÷ n)^(n × t), where P is principal, r is the annual nominal rate, n is periods per year, and t is years.
How are recurring contributions handled?
The calculator adds each contribution at the selected beginning or end of the contribution period and compounds it through the remaining periods.
What is effective annual rate?
Effective annual rate shows the annual growth produced by the nominal rate and selected compounding frequency: (1 + r ÷ n)^n − 1.
Formula and method
Final amount A = P × (1 + r ÷ n)^(n × t). Compound interest = A − P.
Methodology and assumptions
The calculator divides the entered nominal annual rate by the selected number of compounding periods and raises the periodic growth factor over the full tenure. It assumes a constant rate, fixed compounding frequency, and no taxes, fees, withdrawals, defaults, or rate changes.
Authoritative sources
- Financial education guide: borrowing, interest and compoundingReserve Bank of India
Sources last checked September 10, 2026. Regulations and guidance can change; use the linked authority for the current position.
Related tools
Calculation, source, and limitation check completed September 10, 2026 by Ajit Naskar. No independent professional review is claimed.