Mortgage Broker Fee Calculator

Brokers quote fees two ways: a flat amount that does not move with the size of the loan, and a percentage of the loan that does. That single difference decides the comparison. The percentage fee rises in step with the loan, so it sits below a flat quote on small loans and passes it at a crossover, above which the flat quote is the cheaper of the two. The section below sets out where that crossover falls and how to read it from either direction.

Which inputs matter most

The loan amount and the percentage rate are interchangeable in proportional terms: they enter the calculation only as a product, so a 1% increase in either (a proportional change, not a percentage point) moves the percentage fee by exactly 1% of itself, at any price level and any pair of quotes. The gap between the two quotes moves by that same amount, widening where the percentage quote is the dearer and narrowing where the flat quote is, except where the change carries one quote past the other: there, part of the move closes the gap and the remainder opens it again on the far side. The flat quote behaves differently: a unit added to it moves the gap by exactly one unit, subject to the same two qualifications (which quote is currently the dearer, and whether the addition carries it past the other). Which structure costs less does not turn on any of the three individually, only on whether the loan sits above or below the flat fee divided by the rate.

What's happening under the hood

The percentage quote is converted to a cash amount by multiplying the loan by the rate divided by 100, and the two cash amounts are compared. The headline figure is the difference between them, and the label names which of the two is the lower. Nothing else enters: no interest, no term, no timing. Some brokers are paid by the lender instead of, or alongside, the borrower, through a commission commonly described as a procuration fee, and that payment sits outside this comparison, because it is not a cost the borrower pays directly.

Reading the break-even rows

Two rows describe the crossover from opposite directions. The break-even loan amount holds both quotes fixed and solves for the loan size at which they match: the flat fee divided by the rate expressed as a decimal. The break-even percentage rate holds the loan and the flat quote fixed and solves for the rate that would match them, which is also the flat fee expressed as a share of the loan, since the two work out to the same expression. A percentage quote below that rate costs less than the flat quote on this loan, and one above it costs more. Both rows are rounded to two decimals for display, and the exact break-even rate rarely lands on a step the input accepts, so entering the displayed figure back into the tool leaves a small residual gap rather than a clean tie. Both are also computed from the figures entered rather than held inside the panel's own limits, so either can point beyond the range its slider covers, most often the rate on a small loan, or the loan size at a very low rate. The gap row states the difference as a share of the dearer quote, so a third apart reads the same whatever the currency or the price level.

What the comparison leaves out

The calculation covers the broker's own fee and nothing else. Lender arrangement or booking fees, valuation and survey costs, legal and conveyancing fees, insurance premiums, early-repayment charges and the interest accrued over the term are all separate, and several of them are larger than the figure compared here. Those components move independently of how the broker is paid, so a lower broker fee on its own does not settle which arrangement costs less overall.

Where the model stops

The calculation prices a single fee event, with no timing and no discounting, and it takes both quotes exactly as given. A percentage quote carrying a floor or a cap cannot be represented, because the tool applies the rate across the whole range; floors are most common at the small-loan end, where a bare percentage produces a fee too small to cover the work. Where a quote has a floor, the percentage line is understated below the loan size at which that floor binds.

For educational illustration

The comparison models two fee structures at a fixed point in time. It does not account for negotiation, for lender-specific variations, or for changes to fees or terms after the calculation is run.