Complete guide
Investment growth calculator with fees and inflation
Project an initial investment plus monthly contributions, subtract an annual fee drag and translate the ending balance into today's purchasing power. The annual table separates deposits from estimated growth.
How to use the investment calculator
Enter the amount invested today, a regular monthly contribution, the investment period and an assumed annual return. Add estimated fund or advisory fees and inflation rather than comparing projections on gross returns alone.
- Enter the initial balance.
- Add the monthly contribution and years.
- Use a cautious expected return.
- Enter ongoing fees and inflation.
- Compare nominal balance, growth and today's purchasing power.
Compound growth with monthly deposits
The starting balance compounds for the whole period. Each contribution compounds only after it enters the account, so beginning-of-month deposits receive one extra month of modeled growth compared with end-of-month deposits.
next balance = current balance × (1 + monthly net rate) + contributionWhy investment fees matter
Recurring fees reduce the portion of return that remains invested. The SEC warns that even small ongoing fees can have a substantial long-term effect because the removed amount also loses future compounding.
Nominal and inflation-adjusted results
The nominal balance is the future dollar figure. Purchasing power discounts that figure by the entered inflation rate, making long projections easier to compare with present-day spending.
real value = nominal balance ÷ (1 + inflation)^yearsWhat the projection cannot predict
Markets do not deliver a fixed return each month. Sequence of returns, taxes, contribution changes, trading costs and withdrawals can materially change the outcome. Use scenarios rather than treating one result as a promise.
Scenario inputs to compare
| Input | Lower scenario | Base scenario | Higher scenario |
|---|---|---|---|
| Annual return | 4% | 7% | 10% |
| Annual fees | 0.10% | 0.50% | 1.00% |
| Inflation | 2% | 2.5% | 4% |
| Monthly contribution | $250 | $500 | $750 |
Frequently asked questions
What return should I enter?
Use a scenario appropriate to the assets and risk involved. A fixed historical average is not a guaranteed future return.
Are contributions made monthly?
Yes. You can model them at the beginning or end of each month.
How are fees included?
The model applies the entered annual percentage as a recurring drag on growth.
What is inflation-adjusted value?
It expresses the projected balance in approximate present-day purchasing power using your inflation assumption.
Does the result include taxes?
No. Account type, location, gains and withdrawal timing all affect tax treatment.
What to keep in mind
This is a fixed-rate projection, not a forecast or investment recommendation. Returns can be negative and real fees, taxes and cash flows vary.
Results display up to 8 decimal places; exported numbers preserve calculation precision. This is a calculation summary, not an official certificate.