Investment Growth Calculator
Estimate how your investment grows with regular contributions.
What is it?
Investment growth combines an initial lumpsum with ongoing monthly contributions, showing how the two work together through compounding. It's useful when you're starting with existing savings and plan to keep investing regularly.
Formula
Each month, the running balance earns interest and the monthly contribution is added:
Value(month) = Value(month − 1) × (1 + r) + Monthly Contribution
Formula Explanation
This calculator combines two growth patterns: the initial lumpsum compounds on its own from month one, while each subsequent monthly contribution starts compounding from the point it's added. Simulating month by month captures both effects accurately in one combined result.
Example Calculation
Starting with $200,000 and adding $8,000/month at 12% return for 15 years grows to roughly $5,200,000, from a total contribution of $1,640,000.
How to Use
- Enter your initial investment amount.
- Enter your planned monthly contribution.
- Enter the expected annual return.
- Enter the investment duration in years.
- View the final value, total invested, and profit earned.
Benefits
- Captures both an existing lumpsum and ongoing contributions in a single projection.
- More realistic than a pure SIP calculator for investors starting with existing savings.
- Shows exactly how much of the final value comes from your own contributions vs. growth.
Use Cases
- Projecting growth when you have both existing savings and plan to keep investing monthly.
- Comparing scenarios with different starting amounts and monthly contributions.
- Long-term financial planning that accounts for a real starting point.
What Your Result Means
The final value combines growth on your initial lumpsum with growth on every subsequent monthly contribution. The "profit earned" figure isolates how much of that total came from compounding rather than your own money.
Tips
- Setting monthly contribution to zero turns this into a pure lumpsum calculation.
- Try adjusting the initial amount vs. monthly contribution to see which has more impact on your specific timeline.
- Use this alongside the Retirement or Savings Goal calculators for a fuller financial picture.
Common Mistakes
- Forgetting this calculator needs an initial amount — set it to a small number rather than leaving it blank if you're starting from near-zero.
- Using an unrealistically high expected return, inflating the projected outcome.
- Not revisiting the projection as your actual monthly contribution changes over time.
FAQs
Is this the same as a SIP calculator?
It's similar, but it also accounts for an initial lumpsum invested upfront in addition to the ongoing monthly contributions.
What happens if I set the monthly contribution to zero?
The result becomes equivalent to a pure lumpsum investment calculation, growing only the initial amount.
Why combine lumpsum and SIP?
Putting existing savings to work immediately while continuing to invest monthly captures the benefits of both strategies — upfront compounding time and disciplined ongoing investing.
Can I use this for a zero initial investment?
Yes, enter a very small initial amount (like $1) if you're starting purely with monthly contributions — the result will closely match a pure SIP calculation.
This calculator provides estimates based on the expected return you enter. Actual investment returns vary with market performance.
Last updated: July 25, 2026