Glossary · pricing
Parts margin
Parts margin is the gross profit a shop keeps on the parts it sells, expressed as a percentage of parts sales and calculated as parts sales minus parts cost, divided by parts sales.
Also called
- At the counter
- parts gross profit, parts GP, parts gross margin, parts department margin, parts profit percentage
Parts margin is the gross profit a shop keeps on the parts it sells, stated as a percentage of parts sales. Parts sales minus parts cost, divided by parts sales. The IRS describes the same arithmetic for any small business that sells a product, in Publication 334, where gross profit is what is left once the cost of goods sold comes off net receipts. It answers one question, which is how much of every parts dollar a customer hands over stays in the building.
Which number does the report use?
Margin, because that is what a profit and loss statement speaks and what a lender asks for. The matrix that produced the price is written in markup instead, so the same parts department gets described with two different percentages by two different screens. The difference between markup and margin entry carries the conversion, and running it once removes most of the arguments in a shop.
Where does parts margin leak?
Six places, and none of them announce themselves.
- Freight and delivery. A hot-shot run to get a part in by two costs money that lands on the statement and never touches the ticket.
- Cores. An unreturned core charge is a permanent debit with no credit behind it. The old unit also has a second claim on it, because the customer can ask to keep it. Florida makes every written repair estimate carry "a statement allowing the customer to indicate whether replaced parts should be saved for inspection or return". California takes the request at the work order and then carves out the piece your supplier is owed: the dealer returns replaced parts "excepting such parts as the automotive repair dealer is required to return to the manufacturer or distributor under a warranty arrangement", and has to offer to show the customer those instead. Whoever closes the ticket needs to know which box was ticked before the old unit goes in the return bin or the trash.
- Matrix ceilings. Most parts matrix tables flatten the markup on high-cost parts, which is defensible on a $900 alternator and expensive on a $2,800 injector set that goes out at a fraction of the shop's normal margin.
- Cost-plus and fleet accounts. Agreed pricing is fine. Agreed pricing nobody re-reads for four years is a discount that outlived its reason.
- Warranty replacements. A part replaced under your own warranty is a sale at zero, and it belongs somewhere the report can see it.
- Returns. A restocking fee on the turbo that turned out to be the wrong part number comes straight off the job it was ordered for.
Why does the report disagree with the ticket?
The repair order records the cost the counter quoted. The supplier invoice records what the shop was billed. Those two agree less often than anybody wants, because prices move between the quote and the delivery, because freight rides on the invoice and because a substitution went out at a different cost with the same description.
Pick one month and reconcile. Pull closed repair orders against the supplier statement line by line, and the difference between reported margin and real margin stops being a theory. Shops doing this the first time usually find the gap concentrated in a handful of accounts.
How do you set the target?
Backwards, from the money the shop needs. Add up fixed costs and the owner's required return for a month, decide what share of that gross profit the parts side should carry, then divide by the parts sales you expect at your current car count. That produces a target with a reason attached to it.
A shop needing $52,000 of gross profit a month that splits it evenly between departments needs $26,000 out of parts. At $60,000 of parts sales, that is a 43.3% margin. Change the car count or the labor mix and the required number moves, which is why the target gets revisited when the shop changes shape, not when somebody reads an article.
What moves it fastest?
Buying, then the matrix. A shop that gets its high-volume lines onto better jobber pricing improves margin without touching a single customer-facing price, and nobody has to defend anything at the counter. After that comes matrix discipline on the middle of the price range, where the volume lives.
Freight is the third lever and the one nobody pulls. Consolidating two rush deliveries a day into one scheduled run costs an advisor a phone call and takes real money off the cost side of every part on the truck.
Watch the diesel tickets closest. Injector sets, turbochargers and long blocks carry enough cost that one poorly configured ceiling on a single job outweighs a month of oil filters, and those are also the parts with the largest cores attached. The gross profit line on a $9,000 ticket deserves somebody looking at it before it goes out the door.
Back to the glossary, or read how an estimate gets priced.
Questions shops ask
- How do you calculate parts margin?
- Take parts sales, subtract what those parts cost, then divide the result by parts sales. A month with $60,000 of parts sales against $34,000 of parts cost produced $26,000 of gross profit, which is a 43.3% margin. Do it on the same date range your profit and loss statement uses or the two numbers will never agree.
- Why is my reported parts margin higher than my real one?
- Because the repair order stores the cost you were quoted and your supplier bills you what you paid on the day. Freight, price changes between quote and delivery, restocking fees and cores that never went back all land on the statement and never touch the ticket. Reconcile a month of supplier invoices against closed tickets once and you will find the gap.
- What is a good parts margin for a shop?
- Whatever covers your overhead with room left, which is a number you derive rather than borrow. Work out what gross profit dollars the shop needs each month, split it between the parts side and the labor side, then divide the parts share by expected parts sales. A target somebody quoted you at a trade show is not your target.
- Do cores affect parts margin?
- They do when they never go back. An unreturned core is a charge sitting on your supplier account with no credit against it, and if the customer was billed for the core, the shop is holding money against a refund that will not happen. Each one is buried in a different month's statement, so it reads as a slow drift rather than a mistake.
- How much is one point of parts margin worth?
- One percent of parts sales. On $60,000 of parts sales a month that is $600, and $7,200 across a year, for a change nobody in the building would feel on any single ticket. Run the same arithmetic on your own parts sales before deciding how much attention the matrix deserves.