Compound interest (after Belgian tax)

Because in Belgium three levies stand between the gross curve and the money received: the stock-exchange tax on every purchase, the 30% withholding on distributed dividends, and the capital-gains tax since 2026. A gross curve answers a question nobody is asking.

An accumulating class reinvests income inside the fund: nothing is paid out, so there is no yearly withholding tax. A distributing class pays the dividend, 30% is withheld on it, and only the remainder can be reinvested. With no tax at all the two produce exactly the same result.

Yes: the TOB is due on every purchase and every sale alike. On a monthly contribution it applies twelve times a year, at the rate of the instrument type chosen.

Because a gain on an asset held continuously for at least ten years is exempt. On a twenty-year plan, half the contributions have passed that mark by the time of the sale; the annual exemption then applies to what is left.

A constant annual return compounded at one twelfth each month, contributions at the start of the month, no brokerage or management fees, and a single sale at the end. The projection is nominal; the expected inflation rate only restates the final after-tax figure in today's money. Fees have a simulator of their own.