Financial Independence Calculator

Free Financial Independence Calculator: calculate financial independence instantly with transparent formula, worked examples and tips. No signup.

An investment growth calculator projects how a lump sum investment or regular contributions grow over time through compound returns. It is the essential tool for understanding the long-term power of compound growth, comparing investment accounts, planning for financial goals (house deposit, education fund, retirement), and evaluating whether current saving rates are sufficient to meet targets. The principle of compound growth means that returns generate further returns — a small difference in annual return rate, extended over decades, produces dramatically different outcomes. Loan Payment Calculator and Mortgage Calculator provide important inflation and tax context for these projections.

Investment returns are not guaranteed and vary by asset class, time period, fees, and market conditions. Global equities (MSCI World index) have returned approximately 9–10% nominal per year over long periods. Bonds have returned approximately 2–4% nominal. Cash savings have returned approximately central bank rates, which from 2009–2022 were often below 1%. Inflation of 2–3% per year must be subtracted from nominal returns to find real purchasing power growth.

Enter the initial lump sum (or zero if starting from scratch).
Enter regular monthly or annual contributions.
Set the expected annual return rate — 5–7% for a balanced equity fund; 2–3% for bonds; 1–3% for cash/savings accounts. Use real (inflation-adjusted) returns for more meaningful projections.
Enter the investment period in years.
Read the projected final value and total contributions — the difference is the investment return generated.
Try different return rates (±2%) to understand the sensitivity of the projection to the return assumption.

Compound investment growth formula

Future value of lump sum: FV = PV × (1 + r)ⁿ

Future value of regular contributions: FV = PMT × [(1 + r)ⁿ − 1] ÷ r

Combine both formulas for an initial deposit plus regular contributions.

Worked example: 10,000 initial deposit + 500/month contributions, 7% annual return, 20 years. Lump sum FV = 10,000 × 1.07²⁰ ≈ 38,697. Monthly contributions FV ≈ 262,000 (with monthly compounding). Combined ≈ 300,000. Total contributions: 10,000 + (500 × 240) = 130,000. Investment return generated: approximately 170,000.

Interpreting your investment growth result

Rule of 72 — quick doubling time estimate

The Rule of 72: years to double your money ≈ 72 ÷ annual return rate. At 6% return: doubles every 12 years. At 9%: doubles every 8 years. At 2% (cash savings): doubles every 36 years. This illustrates the long-run advantage of equity investment over cash for long-term goals. Note that projected values are in nominal (not inflation-adjusted) terms — apply the compound inflation formula to find the real purchasing power of the projected amount.

Finance tips and best practices

Start as early as possible — an investment started at 25 vs 35 typically generates twice the final value at 65 with the same monthly contribution, purely due to compound time.
Keep investment fees below 0.5% total annual charge — a 1.5% annual fee vs 0.2% costs approximately 20–25% of the final pot over 30 years.
Use tax-advantaged investment wrappers where available in your jurisdiction — sheltering returns from tax significantly improves long-run outcomes.
Automate contributions — regular standing order or direct debit contributions remove the temptation to time markets and ensure consistency.
Do not withdraw during market downturns — selling during a crash locks in losses; missing the 10 best trading days in any decade typically halves the long-run return.

1 invested in global equities in 1970 was worth approximately 250× in real terms by 2024 — approximately 6.4% real compound annual return (MSCI World, inflation-adjusted).
A 0.5% difference in annual fees on 100,000 invested over 30 years costs approximately 45,000 in foregone growth at a 7% gross return.
Time in the market beats timing the market — missing the 10 best trading days per decade typically reduces returns by approximately 50% vs staying fully invested (JP Morgan Asset Management, 2024).
500/month invested for 30 years at 7% annual return produces approximately 590,000 — of which only 180,000 is contributed capital; the remaining 410,000 is compound growth.

Common mistakes to avoid

Using nominal return assumptions without adjusting for inflation — 7% nominal return at 3% inflation is only 4% real growth in purchasing power.
Not accounting for investment management fees — net return after fees is the correct input; always subtract annual charges from the gross return assumption.
Treating investment projections as forecasts — long-run compound return formulas provide planning estimates, not guarantees; actual returns can be significantly different in any 10–20 year period.
Withdrawing from long-term investments for short-term needs — keep short-term needs in a separate emergency fund and treat long-term investment accounts as untouchable.

Investment projections are illustrative mathematical models based on assumed constant rates of return. Past performance does not guarantee future results. Investment values can fall as well as rise and you may get back less than you invested. Investment advice is regulated in most jurisdictions — ensure any investment adviser is authorised by the relevant financial regulator in your country. Investor protection schemes (such as the FSCS in the UK or SIPC in the US) cover eligible investments up to applicable limits. This calculator does not constitute investment advice.