What is compound interest?
Compound interest is growth earned on both principal and previously earned interest.
Compound Interest Calculator
Forecast portfolio growth using principal, annual return, investment duration, and monthly contributions. Use this tool to set realistic savings targets and compare growth scenarios.
Compound Interest Calculator
Estimate future portfolio value with recurring monthly contributions.
Projected future value
Rs 57,140
Total contributions: Rs 35,000
Growth earned: Rs 22,140
Compound Interest Guide
How this compound interest calculator works
This calculator combines a standard compounding formula with monthly contributions so you can model realistic wealth growth. Many projections fail because they focus only on starting principal and ignore ongoing deposits. In long-term planning, consistent contributions often drive more of the final outcome than small changes in compounding frequency.
Use this calculator to test three scenarios: conservative, base, and optimistic return assumptions. Scenario planning prevents overconfidence and helps you choose contribution levels that still work when markets are weaker than expected.
Formula used
Principal growth follows A = P(1 + r/n)^(nt). Contribution growth is modeled using monthly compounding assumptions for recurring deposits. The combined future value equals principal growth plus contribution growth.
For best use, keep assumptions transparent. If fees are expected, lower the annual rate input before projecting future values.
Planning steps and examples
Step 1: Enter current principal and realistic annual return. Step 2: Set years based on your goal timeline. Step 3: Add monthly contributions and review projected future value, total contributions, and growth earned.
Example: A 5,000 starting balance with 250 monthly contributions at 8 percent over 10 years can produce substantial growth. Example: Increasing contributions by 100 per month often improves outcomes more than raising expected return by one percentage point.
Frequently Asked Questions
Can I include monthly deposits?
Yes. This calculator includes recurring monthly contributions in the forecast.
What annual rate should I use?
Use a realistic expected long-term return, not an unusually high short-term return.
Does this include fees?
No. Adjust your expected rate downward to account for fees and taxes.
How many years should I model?
Use the actual horizon of your goal, then run conservative and optimistic scenarios.
What if returns are volatile?
Use multiple scenarios and review the plan annually for risk-aware adjustments.
Is monthly or yearly compounding better?
More frequent compounding helps slightly, but time and contribution size matter more.
Can this help with retirement planning?
Yes. It is useful for retirement, education, and long-term wealth goals.