One HK$6m deal, three layers
Layer one, total commission: price multiplied by the total rate. At 2%, HK$6m gives HK$120,000.
Layer two, the split between agencies: divide HK$120,000 between the listing side and the selling side according to the agreed share. At 50/50, each side is HK$60,000.
Layer three, the split inside each agency: divide each side's HK$60,000 between the agency and its agent. At a 50% agency cut, each agent receives HK$30,000 and each agency retains HK$30,000. The formula is the side's amount multiplied by one minus the agency cut.
All three rates are inputs. The calculator separates them because in practice they are agreed by different people at different times.
Where the rates come from: convention, not statute
In the secondary market, 1% from each side is a market convention within a negotiable range, not a fixed statutory or regulatory rate. Primary market structures move more often: am730 reported in 2024 that the four largest agencies issued internal notices requiring a minimum 2% net commission on new launches from 2024-01-01, and Sing Tao reported even more complex competition on primary commission in a quiet market.
Those are media summaries of market conditions rather than regulatory standards. This article and the calculator publish no standard rate, only the arithmetic. Any rate quoted externally should keep its year and its source.
Four things to settle before splitting
One, the total commission rate and who pays it. Two, the shared ratio and what it stands for, such as which side holds the listing and which side brings the buyer. Three, the agency's cut. Four, whether any rebate or kickback is involved, which is the item most likely to cause disagreement when left unwritten.
Confirm all four in writing when the co-operation starts. This is not legal advice; it simply fixes the inputs to the arithmetic so that no one has a different reading of what should be divided later.
The same deal from the buyer's side
Splitting is the income side. The client cares about the cost side. On the same HK$6m transaction, the buyer's cash requirement is the price plus AVD, the buyer's own commission, the legal fee and miscellaneous costs. Only the buyer's side of the commission counts.
Working both sides together means you can answer a client or a co-broke partner with the buyer's outlay, the total commission and each party's share in one pass, rather than looking the numbers up twice.
Two self-checks
First, make sure all three rates are the agreed figures rather than the defaults. The defaults are only a starting point.
Second, add the layers back up: the two sides should sum to the total commission, and the agency and agent amounts should sum to the side's amount. When a total does not reconcile, a rate has usually been applied twice.