Investment Calculator
Project a lump sum investment with optional yearly additions. See future value, total ROI, and what growth versus contributions actually contributes. Know what you are projecting before you commit to a plan.
Project an investment
Future value, ROI, and CAGR — the three numbers every investor needs
Future value is what the money becomes after compounding — the bottom-line projection. ROI (Return on Investment) is the total percentage gain: your gain divided by what you put in. CAGR (Compound Annual Growth Rate) is the constant yearly rate that would produce the same future value — the apples-to-apples comparison tool for investments of different lengths. A $50,000 investment that becomes $142,000 over 15 years has a 184% total ROI and roughly a 7.3% CAGR. Use ROI to understand total magnitude; use CAGR to compare against other opportunities.
Three scenarios — see what different assumptions produce
Scenario 1 — The IRA Maximizer: $25,000 initial, $7,000/year (2026 IRA limit), 7% for 20 years. Total invested: $165,000. Future value: $440,000. Growth: $275,000 — the market contributed more than you did.
Scenario 2 — The Inheritance Invested: $100,000 lump sum, no additions, 8% for 25 years. Future value: $685,000. Total invested: $100,000. ROI: 585%. The last decade does more work than the first 15 years combined — because the base is so much larger. This is why compounding math seems to accelerate toward the end.
Scenario 3 — The Fee Destroyer: Same IRA Maximizer at 7% gross return. Fund A charges 0.05% (index fund). Fund B charges 1.0% (actively managed). Fund A net 6.95%, final value roughly $437,000. Fund B net 6.0%, final value roughly $385,000. The 1% fee costs $52,000 over 20 years — on a $165,000 investment.
Lump sum vs. dollar-cost averaging — the honest comparison
Historical data gives a clear but nuanced answer. Investing the lump sum immediately outperforms 12-month DCA in roughly 66% of historical 12-month periods, because markets rise more often than they fall. The 34% of cases where DCA wins are concentrated in periods where markets fell sharply right after investing.
The practical answer depends on psychology as much as math. If investing $50,000 all at once and watching it drop 20% the next month would cause you to panic-sell, DCA is the better strategy for you — because panic-selling locks in the loss. If you can hold through volatility, lump sum is mathematically favored. Both are vastly better than leaving money in cash waiting for the perfect moment, which never exists.
Return assumptions — reading them honestly
The US stock market has averaged roughly 10% nominally over long periods. Real-world portfolios receive less because they pay fund expense ratios and hold some bonds. The most defensible long-term planning range for a diversified, low-cost portfolio is 6–8% annually. One percent of return difference over 30 years matters enormously: $50,000 at 6% for 30 years becomes $287,000; at 8% it becomes $503,000. This is why choosing low-cost investment vehicles and staying invested through volatility compounds into large differences over time.
Frequently asked questions
What is the difference between ROI and CAGR?
ROI is total: invest $50,000, end with $115,000 means 130% ROI. CAGR annualizes it: what constant yearly return produces the same result over the holding period. Use CAGR to compare investments of different lengths or against benchmarks like the historical S&P 500 return.
Lump sum or dollar-cost averaging?
Lump sum wins mathematically about 66% of the time because markets trend upward. DCA wins in the remaining cases where markets fell right after investment. The real variable is your psychology — if volatility would cause you to sell, DCA is better. Both beat staying in cash waiting for the right time.
What return should I assume?
6–8% is a defensible range for diversified stock portfolios after costs over long periods. Always model 5%, 7%, and 9% to understand the range — the difference across these assumptions over 20–30 years is enormous and should not be treated as a single number.
How much do fees reduce returns?
A 1% annual fee on a 30-year $50,000 investment at 8% gross return reduces the final balance by roughly $180,000–$220,000. Low-cost index funds with expense ratios of 0.03–0.20% keep that money compounding. Fees are a primary performance determinant.
Does this account for taxes?
No. Tax-advantaged accounts (401k, IRA, Roth) let growth compound untaxed. Taxable accounts face annual tax on dividends and realized gains. Low-turnover index funds in taxable accounts minimize this annual drag.
What is the best investment for a 10-year horizon?
This calculator shows projections but cannot recommend investments — that depends on your specific tax situation, risk tolerance, existing holdings, and financial goals. As a general framework, 10 years is long enough for meaningful equity exposure. A fee-only fiduciary financial advisor can help build a personalized allocation.
How investment return calculations work
Investment calculators project future value using compound interest: FV = PV × (1 + r)^n for a lump sum, plus FV_contributions = C × [(1+r)^n − 1] / r for regular contributions. The most critical insight: time dwarfs every other variable. A 7% annual return doubles money every ~10 years. Starting at 25 vs. 35 with identical contributions produces nearly double the outcome by retirement — despite identical monthly effort.
Three real investment scenarios
Scenario 1 — Index fund 30-year projection: $5,000 initial, $300/month, 7% return. Projected: $354,000. Total contributions: $113,000. Growth: $241,000 — more than double the actual money invested, created purely by compounding.
Scenario 2 — Las Vegas real estate vs. stock market (2010–2024): $44,000 down on a $220,000 Henderson home. Appreciation ~7.5%/year to ~$450,000. Return on invested capital (down payment): over 900%, amplified by mortgage leverage. S&P 500 same period: 13.5%/year total return. Stock market won on rate; real estate won on return per dollar invested through leverage. The comparison changes entirely if comparing all-cash real estate to stocks.
Scenario 3 — Conservative vs. aggressive over 20 years: $50,000 at 45. Conservative (4% return): $109,000 at 65. Moderate (6%): $160,000. Aggressive (8%): $233,000. The difference between conservative and aggressive: $124,000 on the same $50,000 — demonstrating why allocation matters more than almost any other variable for long-term investors.
Realistic return rate expectations
Historical long-run averages: US large-cap stocks (S&P 500) ~10% nominal, ~7% real (inflation-adjusted). US bonds: ~3–4% nominal. Balanced 60/40 portfolio: ~6–7% nominal. For planning, 6–7% is a commonly used conservative equity assumption; 4–5% for balanced; 8–9% for aggressive all-equity. These are averages — any 5–10 year window can differ dramatically in either direction.
Frequently asked questions
What is the difference between nominal and real returns?
Nominal return is the stated percentage gain. Real return adjusts for inflation — it is the growth in actual purchasing power. If a portfolio returns 8% and inflation is 3%, the real return is approximately 5%. The S&P 500's historical real return is approximately 7–7.5%. For retirement planning in today's dollars, use real returns.
Should I invest a lump sum or dollar-cost average?
Research consistently shows lump-sum investing outperforms dollar-cost averaging (DCA) about two-thirds of the time, because markets rise more often than they fall. However, DCA reduces regret if markets drop right after a large investment. For amounts large enough to cause significant regret if invested at a short-term peak, DCA's psychological benefit may outweigh the statistical disadvantage.
How does compounding apply to real estate investment?
Real estate equity compounds on the total property value each year — not just your equity. On a $400,000 property appreciating 5%/year, your annual equity gain is $20,000 regardless of whether you put $40,000 or $80,000 down. This leverage effect can make real estate returns on invested capital (down payment) exceed stock market returns in appreciating markets — though with higher risk and illiquidity. Use the Mortgage Calculator to model your specific scenario.
What is a realistic return for a 5-year investment horizon?
For a 5-year timeline, broad equity exposure carries meaningful risk — the S&P 500 has had 5-year periods with negative real returns. For money needed in 5 years, a conservative allocation (30–50% equities, balance in bonds and CDs) is appropriate. Using 4–5% as a planning assumption for a balanced 5-year portfolio is more prudent than extrapolating long-term equity averages.
Disclaimer: Investment projections are estimates only. Past performance does not predict future results. This is for general educational purposes and does not constitute investment advice. Consult a licensed financial advisor before making investment decisions. Stanley King (NV BS.0143719) is not a licensed financial advisor.