Gross margin by service line is the price of the work minus everything it costs you to deliver that specific work, divided by the price. The number that makes it accurate is your loaded labour rate — what an hour of your team genuinely costs, not what you pay them per hour. Without that figure, every margin calculation in a small business is optimistic by roughly a third.
A single blended margin across the whole business hides the service that loses money on every job. Calculated per line, the picture usually changes which work you want to sell.
Why a Blended Margin Number Misleads You
Your accounts show total revenue and total cost of sales. Divide one by the other and you get a company-wide gross margin. It is a real number and it is nearly useless for decisions.
Suppose you run three service lines at a blended 42% margin. Split them out and one is at 61%, one at 44% and one at 9%. The 9% line may be the one you most actively sell, because it is easy to quote, easy to win and feels like growth. It is consuming the capacity that the 61% line needs.
You cannot see any of that from the blended figure, which is why pricing decisions made from it tend to be wrong in expensive ways.
Step 1: Work Out Your Loaded Labour Rate
This is the figure almost every small business gets wrong, and it dominates margin in any service business.
Take one role. Add up, for a full year:
- Salary or wages.
- Employer taxes and statutory contributions.
- Insurance attributable to that person.
- Vehicle, tools, phone, equipment and software specific to them.
- Training and licensing.
That total is the annual cost of that role. Now calculate the hours they are actually available to bill or deliver. Start from 52 weeks, subtract holiday, public holidays and an honest allowance for sickness. Then subtract non-delivery time — admin, travel between jobs, team meetings, quoting, driving to the supplier. In most small businesses, genuine delivery time is between 60% and 75% of paid time.
Annual cost divided by actual delivery hours gives your loaded rate. It is routinely 1.4 to 1.8 times the raw hourly wage. If you have been quoting against the raw wage, you have been giving away the difference on every hour sold.
Step 2: Build the Cost of Delivery for One Unit
Pick one service line and define its unit: a job, a project, a month of retainer, a single installation. Then cost one typical unit.
Direct labour. Hours required by role, multiplied by each role's loaded rate. Use real hours from a recent completed job, not the hours you quoted. The difference between those two is usually the whole story.
Subcontractors and suppliers. Everything invoiced to you for that specific unit of work.
Materials and consumables. Including the waste. If you order 10% over and use 95% of it, cost the order, not the usage.
Attributable software and tooling. Software used only by that line, divided across the units it supports.
Rework and warranty. Look at the last ten units of this service. How many needed unpaid return visits or revisions? Average that cost in. Rework is a cost of delivery, not an accident.
Add those together and you have the cost of delivery. Subtract it from the price, divide by the price, and that is your gross margin for the line.
Step 3: Compare Lines Side by Side
Lay the results out in one table. Clarity comes from the comparison, not from any single figure.
| Service line | Price | Delivery cost | Gross margin | Margin per delivery hour |
|---|---|---|---|---|
| Line A | $4,000 | $1,560 | 61% | $244 |
| Line B | $2,200 | $1,232 | 44% | $121 |
| Line C | $900 | $819 | 9% | $27 |
The right-hand column matters more than the percentage, because your real constraint is delivery hours, not revenue. A high-percentage service that consumes enormous time can be worth less to you than a lower-percentage service that is quick. Margin per delivery hour ranks the work by the resource you actually run out of.
Step 4: Decide What to Do About the Weak Line
A low-margin line has four possible responses, and the most common mistake is to jump straight to the fourth.
Reprice it. Often the line was priced years ago against costs that have since risen. Work out the price that would produce your target margin and test it on the next three quotes. Existing customers can be moved at renewal with notice.
Re-scope it. The margin may be fine on the core work and destroyed by one element — the site survey, the revisions, the delivery radius. Separate that element and charge for it, or remove it.
Systemize it. If delivery hours are high because the process is improvised, documenting it and removing the rework can move the margin substantially without touching price. Check the gap between quoted and actual hours; a consistent overrun is a process problem, not a pricing problem.
Stop selling it. Valid, but go last. Check first whether the line brings customers who buy profitable work afterwards. A loss-making entry service that reliably leads to a high-margin relationship is a marketing cost, and should be measured as one with a known conversion rate — not assumed.
Step 5: Make It a Monthly Routine
Done once, this is an interesting afternoon. Done monthly, it changes how you price.
Three habits make it sustainable:
Record actual delivery hours per job, even roughly. Without hours, you can never recalculate margin and you are back to guessing.
Review the loaded rate every six months, or whenever wages, insurance or vehicle costs change. A stale loaded rate quietly re-introduces the original error.
Check quoted versus actual on every completed job above a threshold you set. A line where actual consistently exceeds quoted by more than about 15% has a scoping problem that pricing alone will not fix.
What Good Looks Like
There is no universal target margin; it varies enormously by industry and by whether you carry materials, staff and vehicles. What matters more is that you can answer four questions without hesitation.
Which line has the highest margin per delivery hour? Which has the lowest? What is your loaded labour rate per role? What is the average gap between quoted and actual hours?
An owner who can answer those four prices deliberately. An owner who cannot is pricing against competitors and hoping the arithmetic works out.
Start With One Line
Do not attempt the whole business at once. Take your largest service line, cost one recent completed job properly using a loaded rate, and see where it lands. That single calculation usually produces at least one decision worth making immediately.
When you want the full set of numbers in one place rather than one line at a time, work through the Financial Performance Scorecard page — it puts margin alongside cash timing and receivables so you can see which constraint is actually binding.