DCA calculator · S&P 500
Dollar cost averaging calculator
Free dollar cost averaging calculator on real S&P 500 history since 2015 — contributions, ending value, and SteadyGrow adaptive sizing vs blind DCA.
How much would this DCA have been worth?
If you invested $500/week every week into S&P 500 from 2015-01-02 through 2026-09-04, your total contributions would have been about $305,000 and a blind dollar-cost averaging portfolio would be worth about $799,594 (+162.2%) on this historical path — before fees, taxes, or changing the habit mid-stream.
2015-01-02 → 2026-09-04
$500/week · Weekly DCA · S&P 500
What does the chart show?
The chart marks portfolio value over time for blind DCA, SteadyGrow sizing, and (when shown) a same-capital lump sum. Contributed cash rises in steps; ending value is mark-to-market on the last date. SteadyGrow ends about $235,869 ahead of blind DCA on the same long-run budget.
How did we calculate this?
- Window: real market history from our published backtest bundle, typically from 2015 through the latest Friday in the series — we do not invent older decades.
- Contribution calendar: the engine runs on a weekly Friday grid. A “monthly” habit is converted to an equivalent weekly cash rate ((amount × 12) / 52) so the same engine can compare habits.
- Purchase timing: each period’s contribution is applied on that week’s bar in the series (close-based weekly path), not an intraday open fill.
- Assets: S&P 500, Bitcoin, and other series we publish — USD only. No FX conversion.
- Shares: fractional units are assumed. No brokerage commissions, bid–ask, or slippage are modeled.
- Dividends / income: returns follow the wealth path in the backtest bundle for that asset (not a fixed 7–10% toy rate).
- Blind DCA vs SteadyGrow: blind buys the same cash every period; SteadyGrow keeps the same long-run budget but sizes weeks from the model’s multipliers.
- Lump sum (when shown): the same total cash as the DCA habit, invested on day one of the window, then marked to the same path.
Frequently asked questions
- How much would $500/week DCA into S&P 500 have been worth?
- On this page’s window (2015-01-02 → 2026-09-04), blind DCA contributed about $305,000 and ended near $799,594. Change the calculator or a related what-if story for other amounts and start years.
- Is this a forecast or a historical backtest?
- Historical only. We replay published prices from 2015 onward. Past paths do not predict future returns.
- Do you include dividends, fees, and taxes?
- We use the asset’s backtest wealth path (USD) and assume fractional shares with no brokerage fees. Taxes and account wrappers are not modeled — treat the result as a pre-tax illustration.
- Why weekly contributions?
- SteadyGrow’s live product thinks in weeks. Weekly DCA matches payday habits and the Friday series we publish.
- What is the difference between blind DCA and SteadyGrow?
- Blind DCA deploys the same cash every period. SteadyGrow keeps a similar long-term contribution budget but sizes individual weeks using the model — more when valuation/regime looks cheaper, less when stretched.
- Can I compare DCA to investing everything at once?
- Yes — open the DCA vs lump sum calculator. It uses the same total cash: one lump on day one versus spreading buys across the window.
- Where can I learn the basics before I run a calculator?
- Start with our DCA guides — what DCA is, vs lump sum, weekly vs monthly, and crash behavior — then jump back into a historical calculator.
What if your contribution wasn't always the same?
Blind DCA deploys $500/week every period. SteadyGrow keeps the same long-term habit but sizes weeks from valuation and regime — more when markets are cheap, less when they're stretched.