Enter your assumptions
The form uses a single vertical page flow, while fields switch to three columns on large screens, two on smaller screens, and one on mobile.
Example data table
This sample shows how a long-term plan may develop under steady deposits, moderate returns, and small annual increases in contributions.
| Year | Starting Balance | Annual Contributions | Estimated Ending Balance | Real Balance |
|---|---|---|---|---|
| 1 | $25,000.00 | $6,000.00 | $33,212.00 | $32,402.00 |
| 5 | $61,940.00 | $6,752.00 | $74,685.00 | $65,887.00 |
| 10 | $122,814.00 | $7,828.00 | $141,962.00 | $110,171.00 |
| 15 | $205,621.00 | $9,073.00 | $232,447.00 | $159,836.00 |
| 20 | $315,776.00 | $10,518.00 | $352,404.00 | $214,198.00 |
Formula used
1) Effective annual growth from the selected compounding style
Effective annual factor = (1 + r / m)m
2) Monthly growth rate used in the simulation
Monthly gross rate = Effective annual factor1/12 − 1
3) Monthly balance update
New balance = Old balance + contribution + growth − fee
4) Year-end tax estimate
Tax = max(0, yearly gross gains − yearly fees) × tax rate
5) Inflation-adjusted value
Real balance = Ending balance ÷ (1 + inflation rate)years
This approach is designed for planning, not tax filing. It estimates tax drag by charging tax on positive yearly gains after fees, which keeps the calculator practical for scenario comparison.
How to use this calculator
- Enter your starting capital, expected monthly contribution, and investment horizon.
- Set the expected annual return and choose a compounding frequency.
- Add annual contribution growth if you plan to invest more over time.
- Include inflation, tax on gains, and yearly management fees for a more realistic picture.
- Add an annual lump sum if you expect bonuses or extra deposits.
- Enter a target wealth value if you want the calculator to test when you may reach it.
- Press the submit button to see your results, yearly table, and growth chart above the form.
FAQs
1. What does this calculator estimate?
It estimates how an investment portfolio may grow over time using starting capital, recurring deposits, contribution increases, compounding, fees, taxes, and inflation-adjusted purchasing power.
2. Why show both nominal and real balances?
Nominal balance shows future dollars. Real balance adjusts for inflation, so you can compare future buying power more realistically and avoid overestimating what your projected wealth may actually purchase.
3. How is compounding handled here?
The selected compounding frequency first creates an effective annual growth factor. That factor is then converted into a monthly simulation rate so recurring monthly deposits can be modeled smoothly.
4. Are taxes in this tool exact?
No. The tax section provides a planning estimate by applying tax yearly to positive gains after fees. Actual taxation depends on account type, holding period, losses, and local rules.
5. What is the benefit of annual contribution growth?
It helps model salary increases or a stronger savings habit. Even small yearly increases in contributions can significantly improve long-term wealth through compounding on larger future deposits.
6. Should I enter guaranteed returns?
No. Use a reasonable expected long-run assumption instead. Investment returns are uncertain, so it is wise to test conservative, base, and optimistic scenarios rather than trusting one number.
7. Why include management fees?
Fees reduce growth every year. Even a modest annual fee can remove a noticeable amount from long-term wealth because lost money also loses future compounding potential.
8. Can this calculator help with target planning?
Yes. Enter a target wealth amount to see whether your scenario reaches it within the chosen timeline and, if successful, the first projected year it is achieved.