Calculator Inputs
Example Data Table
| Example Input | Value | Example Output | Value |
|---|---|---|---|
| Initial Investment | $10,000.00 | Final Value | $115,496.08 |
| Regular Contribution | $500.00 monthly | Total Contributions | $78,783.28 |
| Years | 10 | Net Gain | $36,712.80 |
| Annual Return | 8.00% | Real Ending Value | $90,225.35 |
| Annual Step-Up | 3.00% | Estimated Fees + Taxes | $7,150.59 |
Formula Used
This calculator uses a month-by-month simulation. It applies the selected compounding frequency, contribution timing, annual contribution step-up, fee drag, tax drag, and inflation adjustment.
1) Monthly growth rate
rm = (1 + r / k)k / 12 - 1
where r is annual return and k is compounding periods per year.
2) Monthly contribution after yearly increase
Cy = C0 × (1 + s)y - 1
where s is the annual step-up rate.
3) Period update
Balance = Balance + Contribution ± Timing, then Growth − Taxes − Fees
4) Inflation-adjusted value
Real Value = Ending Value / (1 + i)years
where i is annual inflation.
Taxes are estimated only on positive gains during each simulated month. This creates a practical planning estimate, not a tax filing figure.
How to Use This Calculator
- Enter your starting investment amount.
- Add the recurring contribution you expect to invest.
- Choose the number of years for the projection.
- Set the expected annual return and compounding frequency.
- Select how often contributions occur and when they are added.
- Include annual step-up, fees, taxes, and inflation if needed.
- Press Calculate Returns to see the results above the form.
- Review the chart, summary cards, annual table, and export buttons.
Frequently Asked Questions
1) What does this calculator estimate?
It projects portfolio growth using an initial investment, recurring deposits, compounding, yearly contribution increases, fees, taxes, and inflation. It helps compare long-term investing assumptions in one place.
2) Is compound return the same as simple return?
No. Simple return ignores growth on earlier gains. Compound return lets gains generate additional gains over time, which usually creates a much larger ending value in longer investment periods.
3) Why do contribution timing options matter?
Money added at the beginning of a period gets more time to grow than money added at the end. Over many years, that timing difference can noticeably change results.
4) How are fees handled here?
The annual fee drag is converted into a monthly equivalent and deducted during each simulated month. This gives a planning estimate of how ongoing portfolio costs reduce ending value.
5) Does this calculator give exact tax results?
No. It estimates tax drag on positive gains during each simulated month. Real taxes depend on account type, holding period, jurisdiction, offsets, and realized versus unrealized gains.
6) What is the inflation-adjusted value?
It shows your ending value in today’s purchasing power. A portfolio can grow in nominal dollars but still lose real buying power if inflation stays high for many years.
7) When should I use contribution step-up?
Use it when you expect future deposits to rise over time, such as through salary growth or higher savings rates. It helps model more realistic long-term investment behavior.
8) Can I use this for retirement planning?
Yes, for scenario planning. It is useful for exploring savings pace, fee drag, and real purchasing power. Still, it should support, not replace, tailored professional financial advice.