TALLIVOInvestment Calculators
Projections, retirement accounts, and — unusually — what the market actually did, on monthly data going back to 1871.
Every projection on this site rests on one assumed number, so here is the measured one: from 1871 to 2026-07, US large-cap stocks returned 9.39% a year with dividends reinvested, or 7.10% a year after inflation. The real figure is the one worth planning on, because it is what the money can actually buy.
It is also an average across 155 years, and no individual investor gets the average — real 10-year stretches have ranged from -5.92% to 19.96% a year. Figures are before fees and taxes, and cover US large-cap equities only.
Start here
- “What will this grow to?” — project a balance with regular contributions. The general-purpose tool, and the right starting point for most questions.
- “What about my 401(k)?” — project it with employer matching and the contribution limit, which a generic growth calculator will get wrong.
- “Roth or Traditional?” — compare them after tax rather than by balance. At the same tax rate they are mathematically identical, which is not what most comparisons will tell you.
- “When can I stop working?” — find the year your portfolio covers your spending, with the 4% rule tested against history rather than assumed.
- “What did this actually return?” — run it against the real record since 1871, including every crash you would have had to sit through.
Why an average is the least useful number here
7.10% a year is the headline, and it describes almost nobody’s experience. The spread around it narrows with time but never closes, and the worst cases are what actually break plans:
| Held for | Worst | Median | Best | Ended ahead |
|---|---|---|---|---|
| 1 year | -58.12% | 8.85% | 151.31% | 69.60% |
| 10 years | -5.92% | 7.02% | 19.96% | 89.00% |
| 20 years | -0.22% | 6.83% | 13.61% | 99.90% |
| 30 years | 1.90% | 6.77% | 11.15% | 100.00% |
Annualised real returns, dividends reinvested, every start month with a complete window. A decade is not the safe horizon it is usually treated as — the worst one lost 5.92% a year for ten straight years. The rolling returns study has the full distribution.
Every investment calculator
- 401(k) CalculatorBalance at retirement with employer match, salary growth, and the IRS contribution limit.
- Capital Gains Tax CalculatorFederal tax on a stock sale — short vs. long term, the 0% bracket, and the 3.8% NIIT.
- Investment BacktestWhat the S&P 500 actually returned since 1871 — real, with dividends, including every crash.
- Roth vs Traditional CalculatorAfter tax, not the balance — at the same tax rate the two are mathematically identical.
- FIRE CalculatorWhen work becomes optional — and whether the 4% rule actually held, tested since 1871.
- Inflation CalculatorWhat money was worth in any year since 1871 — both directions, on the CPI record.
- Compound Interest CalculatorProject investment growth with recurring contributions and a year-by-year chart.
- Dividend / DRIP CalculatorReinvest dividends, grow your share count, and track yield on cost over time.
Going deeper
Three studies built on the same data these calculators run on: what holding periods actually returned, whether investing all at once beats spreading it out (usually, but not in the way that matters most), and what inflation does to a sum of money over a long horizon. Each calculator documents its formula and assumptions on a methodology page.
Common questions
What return should I assume when projecting investments?
Which calculator should I start with?
Is nominal or real the right number to use?
Is the 4% rule safe?
Do these account for taxes and fees?
US large-cap equities only, before fees and taxes. Historical returns describe what already happened and are not a forecast. Source: Robert J. Shiller, Online Data (shillerdata.com) — S&P Composite, dividends and CPI, monthly from 1871. Estimates for general information only — not financial, tax, or investment advice.