Investment Comparison
Compare different investment strategies & expected returns. Analyze stocks, bonds, mutual funds & savings. Choose the best plan for your financial goals.
Strategy A (e.g. Stocks)
Strategy B (e.g. Bonds)
About Investment Comparison
Free Online Tool
Investment Comparison
Enter the initial amount, monthly contribution, annual return, and duration for two investment scenarios — get an exact future value comparison, total interest earned, and a recommendation on which investment strategy builds more wealth.
How to Use This Tool (30 Seconds)
- 1Enter Initial Amount for Both Investments: Input the lump-sum starting capital for Investment A and Investment B. This is the amount you invest on day one. Enter 0 if you are starting with no initial deposit and building purely through monthly contributions.
- 2Set Monthly Contribution: Enter the fixed amount you plan to add to each investment every month. This field is where compounding becomes most powerful — consistent contributions on a lower-return investment often outperform a higher-return investment with irregular deposits.
- 3Enter Annual Return Percentage: Input the expected annual percentage return for each investment. Use historical averages as your guide — broad stock index funds average 7–10% annually over 20-year periods; bonds average 3–5%; savings accounts 1–2%.
- 4Set the Duration in Years: Enter the number of years each investment will run. Both investments do not need the same duration — comparing a 10-year bond ladder against a 20-year equity portfolio is a valid and useful comparison.
- 5Read the Comparison Result: The tool calculates future value, total contributions, total interest earned, and effective return multiple for both investments side by side, then recommends which delivers superior wealth-building outcomes.
Risk vs. Reward Spectrum
Higher potential returns always come with higher potential for loss.
The Compound Interest Formula Behind the Results
The tool calculates future value using the compound interest formula with regular contributions — the same formula used by financial calculators, retirement planning tools, and the SEC's investor education resources:
// Monthly interest rate from annual return
monthlyRate = annualReturn (%) ÷ 100 ÷ 12
// Total number of compounding periods
n = durationYears × 12
// Future value of initial lump sum
FV_lump = initialAmount × (1 + monthlyRate)^n
// Future value of monthly contributions (annuity)
FV_contributions = monthlyContribution × (((1 + monthlyRate)^n − 1) ÷ monthlyRate)
// Total future value
totalFV = FV_lump + FV_contributions
// Example: $5,000 initial, $300/mo, 8% return, 20 years
monthlyRate = 0.08 ÷ 12 = 0.006667
FV_lump = 5,000 × (1.006667)^240 = $24,647
FV_contrib = 300 × ((1.006667)^240−1) ÷ 0.006667 = $178,968
totalFV = $203,615 | Total contributed: $77,000 | Interest: $126,615
The split between FV_lump and FV_contributions reveals a counterintuitive truth: in the worked example above, $5,000 invested upfront grew to only $24,647 — while $300 monthly for the same 20 years produced $178,968. Monthly contribution frequency dramatically outweighs lump-sum size over long durations due to the compounding effect of recurring deposits. The tool surfaces this gap explicitly so you can see where your wealth is actually being built.
Annual Return Benchmarks — By Asset Class
| Asset Class | Historical Annual Return | Risk Level | Suitable Duration |
|---|---|---|---|
| S&P 500 Index Fund | 7–10% (inflation-adjusted) | Medium–High | 10+ years |
| Diversified Bond Fund | 3–5% | Low–Medium | 3–10 years |
| Real Estate (REIT) | 6–9% | Medium | 7+ years |
| High-Yield Savings | 1–5% (variable) | None | 0–3 years |
| Crypto (BTC/ETH) | 20–50% (highly volatile) | Extreme | Speculative only |
| Certificate of Deposit | 2–5% (fixed) | None | 1–5 years |
Historical return figures sourced from Vanguard, Morningstar, and Federal Reserve Economic Data (FRED). Past performance does not guarantee future results. Inflation-adjusted S&P 500 returns based on 1926–2024 rolling 20-year period averages.
⚡ Pro Tip
When two investments show similar future values, always check the total interest earned figure — not just the final number. An investment returning $200,000 on $150,000 in total contributions earned $50,000 in interest. An investment returning $200,000 on $80,000 in contributions earned $120,000 in interest — the same final value but 2.4× the wealth creation efficiency. This ratio, called the return multiple, is the true measure of an investment's compounding power. A higher return multiple at the same final value means your money worked harder — you contributed less to achieve the same outcome, freeing capital for other uses along the way.
Disclaimer: This tool is for informational and educational purposes only and does not constitute financial or investment advice. Future value projections assume a constant annual return rate, which real investments do not guarantee. Actual returns vary based on market conditions, fees, taxes, and inflation. Consult a registered investment advisor (RIA) or certified financial planner (CFP) before making investment decisions.
Frequently Asked Questions
Q: What annual return percentage should I use for a stock index fund?
Use 7% for a conservative inflation-adjusted projection based on the S&P 500's historical average from 1926–2024. Use 10% for nominal returns before inflation adjustment. Financial planners most commonly use 6–8% for long-term retirement projections to account for fees, taxes, and sequence-of-returns risk in real portfolios.
Q: Does the tool account for investment fees or expense ratios?
No — the tool uses a gross return rate. To approximate net-of-fee returns, subtract your fund's expense ratio from the annual return percentage before entering it. A fund with a 10% historical return and a 0.5% expense ratio should be entered as 9.5%. Over 20 years, a 0.5% fee difference reduces final portfolio value by approximately 10%.
Q: What is the impact of starting 5 years earlier on the final value?
Starting 5 years earlier is one of the highest-leverage decisions in personal investing. On a $300/month contribution at 8% annual return, starting at 25 instead of 30 produces approximately $125,000 more at age 65 — from 60 extra monthly contributions of $300, totaling $18,000 in additional deposits generating over $100,000 in additional compounded growth.
Q: Can I compare a short-term and long-term investment in the same tool?
Yes — Investment A and Investment B can have completely different durations. Comparing a 3-year high-yield savings account against a 20-year index fund is a valid comparison. The tool shows future value at each investment's respective end date, making the time-value tradeoff between them explicit and quantified.
Q: Why does monthly contribution have a bigger impact than initial amount over long durations?
Each monthly contribution begins compounding from the moment it is deposited. Over 20 years, hundreds of individual deposits each generate their own compounding curve. The initial lump sum only compounds once from day one. As duration increases, the cumulative compounding effect of recurring deposits grows exponentially relative to a fixed starting amount — this is why pension funds and index fund investors emphasize contribution frequency over starting capital.
Q: What return rate should I use for a conservative comparison?
For a conservative scenario, use 4–5% annually — reflecting a balanced portfolio of index funds and bonds. For a worst-case planning scenario, use 3% — approximately the long-run average of a bond-heavy portfolio after inflation. Planning with a conservative rate and achieving a higher actual return is a much safer position than planning optimistically and falling short.
Q: How does inflation affect the comparison results?
The tool calculates nominal future value — the dollar figure before inflation adjustment. To see real purchasing power, subtract expected annual inflation (historically 2–3%) from your annual return percentage before entering it. A 9% nominal return with 3% inflation is entered as 6% to produce an inflation-adjusted future value that reflects genuine purchasing power growth.