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Dollar-cost averaging calculator
Project a monthly contribution plan against a one-off investment, with real (inflation-adjusted) output and a contribution-vs-growth breakdown.
Invest immediately
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Average in
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Difference
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Portfolio path
Immediate
Averaged
Money contributed
Where the final number comes from
No account, no tracking of your inputs: this tool is plain JavaScript and every number stays on your device.
About this tool
Does dollar-cost averaging beat investing a lump sum?
Historically, on average, no — because markets rise more often than they fall, money invested earlier is exposed to growth longer. Vanguard's research on US, UK and Australian data found immediate lump-sum investing outperformed a 12-month averaging schedule roughly two-thirds of the time. DCA is a behavioural and risk-timing tool, not a return-maximising one.
What return rate should I put in?
Use a range, not a point estimate. A common conservative frame for a globally diversified equity portfolio is 4–7% real (after inflation). Anything above 12% nominal as a long-run assumption should be treated as a stress test, not a plan.
Is my data sent anywhere?
No. Every calculation runs in your browser with JavaScript. Nothing is uploaded, stored or logged.