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Should I invest all at once or dollar-cost average?

You have a lump of money. Do you invest it all today, or feed it in over months? Pick a market scenario and see how both strategies play out on exactly the same price path — then check the table, which runs every scenario at once.

Your money

INPUTS
$
mo
yrs
%

The underlying trend the scenario moves around. Can be negative.

%

Optional. Money queued to be invested usually sits in a savings or money-market account rather than at zero — what that actually earns.

Averaging wins when prices fall first. Lump sum wins when they rise.

How each finished

RESULT
🧮

Enter an amount and how many months you'd spread it over.

Save or send these numbersEmail

All four happen in your browser. Your figures are not sent anywhere — the email opens in your own mail app, already filled in.

Why lump sum usually wins, and when it does notA written guide to the rules behind this calculator →
For educational purposes only. The market scenarios are illustrative price paths, not forecasts — nobody knows which one the next year looks like. Vanguard's study of the US, UK and Australian markets found lump-sum investing beat twelve-month averaging about two-thirds of the time. Not investment advice.