Writing the Divisor Next to the Number
One sentence beside the rate ends most costing disputes. What it has to contain, where it has to appear, and what happens when it is missing.
One sentence next to a labour rate settles most arguments about it: what the cost is, which hours it is divided by, how many of those there are, and the date. Twenty-five words, and their absence is why two people can both be right about the cost of an hour and differ by half.
The practical lesson in “Writing the Divisor Next to the Number” is that a convenient number should begin a review rather than end one. A team assessing explore the time-recording setup for how to calculate idle time can add timely time and project context, with transparent settings, proportionate access and a documented correction process around every material use.
This note is the assembly of the section. It is a filing habit rather than an analytical technique.
Teams documenting “Writing the Divisor Next to the Number” may use GOV.UK payroll guidance as an independent reference. A useful source should prompt a specific check rather than replace case-by-case judgement.
The sentence
£36.92 per chargeable hour. Loaded cost £47,400 over 1,284 budgeted chargeable hours per full-time person. Effective 1 April 2026.
Four facts: the rate, the numerator, the divisor with its size, and the date.
Why each one is there
The rate alone travels and is misquoted. The numerator says what is inside. The divisor says what the rate must be multiplied by to recover the cost. The date says which version this is.
Remove any one and a predictable confusion follows.
Where it has to appear
In the costing policy, on the rate card, in the quoting tool, and in the footer of any report that uses the rate.
Not in a separate document. The sentence has to travel with the number, because the number will travel.
The quoting tool is the important one
Because that is where the rate is used by people who did not build it, and where a misunderstanding becomes a price.
A tool that shows the rate without its basis invites the user to compare it with any other number they have.
What happens without it
Somebody compares the rate to an agency invoice rate. Somebody else compares it to the wage. A third person uses it for capacity planning. All three are wrong in different directions, and none of them can tell.
The second sentence, for mixed populations
"This is a blended rate across full-time and part-time staff; part-time hours carry a higher per-head cost."
Where a blend is used, saying so is what prevents it being read as a measurement of any particular person's hour.
The third sentence, for the cautious
What the rate may not be used for. "Not a marginal cost; not valid for make-or-buy comparisons without adjustment."
Two clauses that prevent the two commonest misuses, both of which have their own notes later here.
Making it hard to avoid
Put it in the template. A rate card without the sentence should look unfinished, in the way a figure without units looks unfinished.
Templates enforce habits that policies do not.
What to do when somebody disputes the rate
Show them the sentence, then the build-up. Almost every dispute is either about the divisor — which the sentence answers — or about a single line in the build-up, which can be looked at.
Disputes about "the rate being too high" in general have nowhere to go and are usually about something else.
The version history
Each sentence kept with its date, superseded rather than overwritten. A short file, appended to annually.
It is also the fastest way to answer the question of why a job costed in 2024 and the same job costed now differ.
The question that tests it
Hand the rate to somebody who did not build it and ask what it would have to be multiplied by to recover the department's cost.
If they can answer from the sentence beside the number, the sentence is doing its job. If they have to ask, something is missing from it, and that something is what the next person will get wrong.
Why it has to be one sentence
Because anything longer does not get copied. A paragraph of qualification stays in the policy document; a sentence travels with the number into the quote, the email and the slide.
The discipline is to decide which four facts matter and to let the rest live in the build-up for anybody who asks.
What the sentence prevents, in order of frequency
Comparison with the wage. Comparison with an agency invoice rate. Use for capacity planning. Use as a marginal cost. Quoting a superseded version.
Five confusions, all common, all addressed by naming the numerator, the divisor, its size and the date. It is the cheapest control in the whole discipline.
What this section has argued
That the denominator is a choice, that the choice moves the rate by fifty per cent, that nobody writes it down, and that writing it down costs a sentence.
Everything else in this collection is a layer in the numerator or a decision about where an hour lands. This is the one line that makes any of it checkable by somebody who was not there.