Investment growth calculator
Build a transparent compound-growth scenario from the amounts and rates you enter—then separate contributions, modeled growth, fee drag and inflation.
Fixed-rate mathematical illustration only. It excludes volatility, taxes, transaction or performance fees, withdrawals and irregular cash flows. It is not a forecast, guarantee or recommendation.
Annual projection
| Year | Opening | Contributions | Growth before fees | Fee drag | Ending | Inflation-adjusted |
|---|---|---|---|---|---|---|
| 1 | $10,000 | $6,000 | $890.15 | $67.87 | $16,822.28 | $16,411.98 |
| 2 | $16,822.28 | $6,000 | $1,372.46 | $109.12 | $24,085.61 | $22,925.03 |
| 3 | $24,085.61 | $6,000 | $1,888.53 | $155.62 | $31,818.53 | $29,546.66 |
| 4 | $31,818.53 | $6,000 | $2,440.73 | $207.88 | $40,051.37 | $36,284.56 |
| 5 | $40,051.37 | $6,000 | $3,031.58 | $266.48 | $48,816.47 | $43,146.64 |
| 6 | $48,816.47 | $6,000 | $3,663.79 | $332.03 | $58,148.23 | $50,141.04 |
| 7 | $58,148.23 | $6,000 | $4,340.26 | $405.2 | $68,083.29 | $57,276.1 |
| 8 | $68,083.29 | $6,000 | $5,064.07 | $486.71 | $78,660.65 | $64,560.46 |
| 9 | $78,660.65 | $6,000 | $5,838.56 | $577.37 | $89,921.84 | $72,002.97 |
| 10 | $89,921.84 | $6,000 | $6,667.26 | $678.03 | $101,911.06 | $79,612.76 |
Included
- An initial balance and fixed monthly or annual contribution
- A fixed annual return assumption, including supported negative values
- A fixed annual percentage fee applied to the invested balance
- Beginning- or end-of-period contribution timing
- An optional entered inflation assumption
- Nominal, inflation-adjusted and no-fee comparison values plus an annual table
Not included
- Market volatility, changing returns and sequence-of-returns risk
- Tax, transaction fees, tiered fees, withdrawals and irregular cash flows
- Guarantees, probability ranges, product comparison or investment recommendations
What this means
The calculator converts the entered annual return and fee into equivalent period factors, then applies them to each monthly or annual period. Beginning-of-period contributions receive that period's modeled change; end-of-period contributions do not.
Fee drag is not just the fees removed. It is the difference between two otherwise identical paths: one with the entered annual fee and one without it. That comparison also captures modeled growth no longer earned on amounts lost to fees.
The inflation-adjusted value divides the ending nominal balance by the compounded inflation factor. It expresses the result in today's purchasing-power terms under one fixed assumption; it is not a forecast of prices or personal living costs.
Formula & worked example
gross period factor = (1 + annual return)^(1 ÷ periods per year) fee period factor = (1 − annual fee)^(1 ÷ periods per year) net period factor = gross factor × fee factor ending balance = repeated contributions and balances × net period factor fee drag = no-fee ending balance − fee-adjusted ending balance inflation-adjusted value = nominal ending balance ÷ (1 + inflation)^years
10,000 initially, 500 at each month-end for 10 years, with 7% return, 0.5% fee and 2.5% inflation
- Periods
- 120 monthly periods
- Total contributed
- 70,000
- Contribution timing
- End of each month
The calculator compounds both the fee-adjusted and no-fee paths period by period and reports their difference as modeled fee drag.
How this calculation works
The calculation follows the formulas, definitions and assumptions explained on this page. The references below support the method and any stated boundaries.
Official sources
- Investor.gov — compound interest tools — Compounding as a way to illustrate how invested money can grow over time
- Investor.gov — how fees affect a portfolio — Ongoing percentage fees reduce the balance that remains invested and can materially reduce long-term value
- U.S. Bureau of Labor Statistics — purchasing power and constant dollars — Adjusting a future nominal amount to express purchasing power after an entered inflation rate