Contribution splitter — what each extra fund costs

The target weights are normalised against their own total, so they do not have to add up to a hundred, and the contribution is divided in those proportions. Each resulting amount is then priced through your broker's published tariff for a single purchase, which is where the arithmetic stops being proportional: a fixed minimum charge applies to a fifty euro slice exactly as it does to a five hundred euro one. The totals show the commission as a share of the whole contribution, and the alternative box reprices the same annual money bought quarterly instead of monthly, which pays the tariff a third as many times.

The amounts here are exact, with no rounding to whole shares, because rounding needs a live price and this site does not republish prices. Real purchases either buy fractional units where the broker supports them or round down, so the split you get is close to this rather than identical to it. Only the commission is priced: custody charges, the bid-ask spread and any currency conversion fee are outside it, so treat the figure as the floor on the cost of trading rather than its total.

How many funds is too many for a monthly contribution?

There is no universal number, but there is a test you can apply here. Raise the fund count until the commission share of the contribution approaches the ongoing charge you were trying to optimise by adding the fund. A portfolio split four ways to shave two basis points off a blended ongoing charge, while paying half a percent to assemble it every month, has moved backwards, and this page shows both numbers in the same unit.

Is buying quarterly instead of monthly worth the delay?

Frequently yes on a flat-fee broker, and the comparison box gives you the saving in euros per year. What it costs is time in the market: the money sits uninvested for an average of six weeks longer per contribution. The cost of that delay is small over a long horizon and the commission saving is immediate and certain, which is an unusual trade to be offered. The cost of waiting page prices the other side of it if you want both numbers.

Why does the tool not size the number of shares?

Because it would need a live quote for each fund, and republishing European end-of-day prices requires a display licence this project has deliberately not bought. Without a price there is no rounding step, and without rounding there is no drift between the target weights and what you can actually buy. What remains is the part that changes a decision anyway, which is the commission.

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