DCA vs Lump Sum Calculator

Illustrate monthly investing against one lump sum on a price path you set, including what fees take.

Your Plan

Invested each month

The lump sum is this times the number of months.

Number of months

months

Between 2 and 240. Ignored if you type your own prices.

The Price Path

How prices move

Price in month 1

Change by the middle month

Negative for a fall, e.g. -20.

Change by the last month

Measured from the month 1 price.

My monthly prices (if chosen above)One price per month, separated by commas or spaces. Made-up prices are fine.

Fees And Cash

Flat fee per buy

Percentage fee per buy

How the two combineCopy the rule from your provider's fee page. Set both to 0 to see the result without fees.

Interest on cash waiting to be invested (optional)

% a year

Only matters if you hold the full sum today and feed it in monthly. Savings account and T-bill rates change; check the current rate.

Monthly investing ends at (illustration)–

Lump sum at the start ends at: –
Difference (monthly minus lump sum): –
Total put in, both ways: –

–

Units And Average Cost

Units bought monthly: –
Units bought as a lump sum: –
Your average cost per unit (monthly, incl. fees): –
Average of the monthly prices: –
Lump sum cost per unit (incl. fee): –

Fee Drag

Fees paid, monthly plan: –
Fee paid, lump sum: –
Monthly fees as a share of each buy: –
Interest earned on waiting cash: –

The Bumpy Part

Largest paper loss along the way, monthly: –
Largest paper loss along the way, lump sum: –

Month By Month (Monthly Plan)

Month	Price	Fee	Units bought	Units held	Put in so far	Value

How To Read The Result

Dollar-cost averaging means investing the same amount at regular intervals whatever the price. A fixed sum buys more units when the price is low and fewer when it is high, so your average cost per unit ends up below the simple average of the prices you paid. That is arithmetic, not a promise of profit: if the price ends lower than your average cost, you still lose money.

A lump sum puts all the money to work on day one. If prices rise from there, it usually ends ahead, because more money was invested for longer. If prices fall first, as in the default path, monthly buying can end ahead. Vanguard's 2023 study of global shares from 1976 to 2022 found a lump sum beat a three-month cost averaging plan about two-thirds of the time, while cost averaging had smaller falls in the worst periods.

Most people in Singapore invest monthly because that is when their pay arrives, not because they are holding a lump sum back. For them, the useful lines are the fee drag and the bumpy part: small monthly buys with a minimum fee lose a bigger share to costs, and the largest paper loss shows what you would have needed to sit through.

This page is an illustration with prices you choose. It is not a forecast and not advice on what to buy.

Assumptions And Limits

The prices are your own illustration, not a forecast and not guaranteed. Real prices do not move in straight lines, and investments can lose money. Past or assumed paths say nothing about what will happen.
Both approaches invest the same total. The lump sum goes in on month 1 at the first price; the monthly plan buys the same amount every month at that month's price. Both are valued at the last price.
Units can be fractional, as with funds, regular savings plans and fractional shares. Buying in SGX board lots would leave some cash uninvested.
Fees are charged on every buy using the rule you pick. Exchange fees, GST, spreads, fund expense ratios, currency conversion, dividends and tax are left out unless you add them to the fee.
Cash waiting to be invested earns the interest rate you enter (0% by default), credited monthly and kept as cash.

This calculator was built with AI tools from published rules and may contain errors. Results are estimates for education only, not financial advice and not a guarantee. Rates and rules change; confirm with the official source before you act. Your figures stay in your browser: nothing you type is sent to us.