If you'd invested then, what would you have now?
One tool, eleven asset classes, every flavor of "what if I had". Lump sum, monthly contributions, both at once, or the equivalent of a loan payment. Compare two scenarios on the same chart.
Total-return data through Apr 2026 · Shiller, FRED, BLS CPI-U, Yahoo Finance
Worth exploring
Notable historical scenarios.
Click any card to load it into the calculator. Use the history to stress-test the kind of investor you'd actually be.
Methodology
How this is calculated.
- Returns include reinvested dividends.
- Total-return indices are used throughout — not price-only. A 4% S&P dividend in 1980 buys more 1980 shares, which compound.
- Inflation uses CPI-U from BLS.
- "Real" returns deflate end-of-period dollars to the start month's purchasing power. Inflation-stepped contributions are scaled by the CPI ratio month over month.
- Lump-sum vs. DCA math.
- Lump sums buy notional shares at a single month's index. Monthly contributions buy fractional shares each month at that month's index. CAGR is annualized, money-weighted (IRR).
- Loan-payment-equivalent mode.
- The standard amortization payment is computed once and then treated as a fixed monthly contribution for the full term. It models the foregone-investment cost of a payment, not the loan itself.
- Different assets, different histories.
- Dates outside an asset's coverage are clamped. NASDAQ starts Jan 1985. Emerging markets start Apr 2003. Date pickers reflect this.
Sources: Robert Shiller's S&P 500 dataset (1871–2023, extended via SPY), Yahoo Finance (Dow / NASDAQ / international / bonds / REITs / gold), FRED CPIAUCSL (inflation), Vanguard mutual fund history (US total market splice). All series are total-return where applicable.
Reference
Annualized returns by decade
| Decade | Annualized | $10K → $ |
|---|---|---|
| Loading… | ||
"—" means the decade falls outside S&P 500's coverage window.
Common questions
About the calculator
Are dividends reinvested?
Yes. The underlying total-return indices already include reinvested dividends, so there's no toggle to flip — the math reflects the standard 'how much would I have' answer.
Do these returns include taxes or fees?
Why does my answer differ from another calculator?
What's CAGR?
What's the difference between nominal and real returns?
Why does max drawdown matter more than total return?
Can I model individual stocks?
Why no crypto?
Is this projecting future returns?
What about taxes on dividends?
How accurate is the data?
Why is the loan-payment mode useful?
Can I share my scenario?
How do I use the comparison feature?