Tool · calculator
Parts matrix calculator
Build a sliding parts matrix band by band, see the margin each markup leaves, and price any part against the table you just built.
What you walk away with
- Outcome
- A parts matrix you can edit band by band, with the margin and a worked price for every band in it.
- Time
- About 10 minutes
A parts matrix is a table of cost bands, each carrying its own markup, that turns what a supplier charges you into what the customer pays. Build yours in the calculator below. Every band shows the margin it leaves and a worked price, and the bottom of the tool prices any single part against the table.
Key takeaways
- Markup slides down as cost climbs, because the dollars climb anyway.
- Every band has a margin, and it is never the same number as the markup.
- Build the matrix off your cost after supplier discount.
- The top band has no ceiling, so no part can fall off the end of the table.
Parts matrix calculator
Six cost bands with their own markup. Change any of them and the table below re-prices.
| Cost from | Cost up to | Markup | Multiplier | Margin | Worked example |
|---|---|---|---|---|---|
| $0.00 | 3 | 66.7% | $5.00 → $15.00 | ||
| $5.00 | 2.5 | 60.0% | $25.00 → $62.50 | ||
| $25.00 | 2 | 50.0% | $75.00 → $150.00 | ||
| $75.00 | 1.75 | 42.9% | $200.00 → $350.00 | ||
| $200.00 | 1.55 | 35.5% | $500.00 → $775.00 | ||
| $500.00 | and up | 1.4 | 28.6% | $1,000.00 → $1,400.00 |
Your cost for the part, and the matrix picks the band.
The arithmetic
- Band
- $86.40 falls in the band up to $200.00
- Selling price
- $86.40 × (1 + 0.75) = $151.20
- Gross profit
- $151.20 − $86.40 = $64.80
- Margin
- $64.80 ÷ $151.20 = 42.86%
The bands this loads with are a starting structure to edit, not a recommendation and not a benchmark. What your matrix should say depends on your suppliers, your mix and what you can defend at the counter, and none of that is knowable from a web page.
Everything above is computed in this browser. Nothing you type is stored or sent anywhere, and there is no field asking for your email.
What does a matrix replace?
A person deciding. Without one, a service writer prices a five dollar grommet and a fourteen hundred dollar transmission cooler using the same instinct, on a Tuesday, with three people waiting. The prices come out inconsistent within the week and indefensible within the month.
The table makes that decision once, in an office, with the calculator open. After that the pricing is mechanical and the writer's job is to sell the work.
How do you set the bands?
Start from your own invoices. Pull a quarter of parts purchases and sort them by unit cost. Look at where the counts pile up, because that is where your bands have to be narrow. A single band holding a third of everything you buy is one band doing four bands' work.
Then set a markup for each band and read the margin column. Work down the table and check that the price on a real part from that band is a number you would say out loud to a customer. If it is not, the band is wrong and no amount of averaging will fix it.
| Band shape | What it is for | The failure it prevents |
|---|---|---|
| Narrow bands under $25 | Clips, seals, hardware | Selling a $2 part for $2.60 |
| Mid bands to $200 | The bulk of a normal ticket | One markup covering a tenfold cost range |
| Wide band above $500 | Turbos, injectors, assemblies | Pricing yourself out of big-ticket work |
| One open band at the top | Everything above the last ceiling | A part with no rule at all |
Why does markup fall as cost rises?
Because the dollars do the climbing on their own. A two hundred percent markup on a four dollar clip earns eight dollars of gross profit. A forty percent markup on a nine hundred dollar injector earns three hundred and sixty. Holding the percentage flat across the table would put your expensive work far above what a customer can find with a phone, and the gain from it would be small next to what you lose in declined jobs.
The slide is also the reason a matrix beats a single number. One markup applied to a whole catalog is a matrix with one band, and it is wrong at both ends at once.
What margin does each markup leave?
Less than the number people expect, and the gap grows as you move down the table. The margin column in the calculator does that conversion on every band while you type, so you can see what a band will report as before you commit to it. The markup versus margin calculator carries the arithmetic itself and converts in both directions.
This matters at review time. A shop that sets its matrix by margin targets and reports on it by markup gets two figures that disagree by more the further down the table it looks, and somebody eventually concludes the matrix is broken.
Publication 334 gives a small business a way to check the two against each other. Its test is to "divide gross profit by net receipts", then to "compare this percentage to your markup policy". Little or no difference between them means the books and the pricing agree. Your matrix is the markup policy in that sentence.
Where do matrices go wrong?
Building off list price is the one that costs the most. The jobber price or the list price will produce a working table on day one. Then the catalog moves, and your selling price follows a number somebody else sets.
Silent drift is slower and harder to see. Costs rise, parts migrate upward into bands carrying lower markup, and blended parts margin falls without a single decision being made. Re-pull your purchase history once a year and look at where the counts sit now.
A core charge has no business in the table at all. It is a refundable deposit, so marking it up charges a customer for money the shop hands back. California writes that out on the one core every shop sells. A replacement lead-acid battery bought without a trade-in carries a deposit the dealer has to "display the amount of the deposit separately on the receipt" and refund when the used battery comes back inside 45 days. A deposit shown on its own line is a deposit no multiplier can reach.
Sublet stays out for a different reason. Somebody else set that price, and California makes you say so on the estimate: the repair dealer has to include "a statement of any automotive repair service that ... will be done by someone other than the dealer or his or her employees". Run a machine shop bill through your parts bands and you are marking up an invoice you did not write, on a line the customer was told came from outside.
Checking the table against your own history
Take thirty closed tickets and re-price their parts through the new matrix. Compare the total to what those tickets billed. A matrix that lifts the total by a few percent is a real change; one that lifts it by a third will show up as declined work before it shows up as gross profit.
For the definitions behind all of this, see the parts matrix glossary entry. The pricing workflow the matrix sits inside is in how an estimate gets priced, and the rest of the calculators are on the tools hub.
Questions shops ask
- What is a parts matrix?
- A table of cost bands, each with its own markup, that turns a supplier cost into a selling price without anybody deciding case by case. A ten dollar sensor connector and a two thousand dollar turbocharger land in different bands and get very different treatment, which is the whole reason the table exists.
- Why does markup fall as part cost rises?
- Because gross profit dollars climb with cost even when the percentage drops. Doubling a four dollar clip earns four dollars. Adding thirty percent to a nine hundred dollar injector earns two hundred and seventy. The same percentage across every band would price the expensive end of the catalog out of the market for no gain a customer can see.
- How many bands should a matrix have?
- Enough that no single band spans an order of magnitude in cost. The calculator loads with six, which is a starting structure and nothing more. What matters more is that the bands are dense at the cheap end, where a small change in markup moves the price by pennies and nobody argues.
- Does a matrix apply to every part on the ticket?
- Carve out anything you sell against a published competitor price, because a matrix cannot see what the shop down the road is advertising this week. Sublet gets its own treatment. So does a core charge, which is a deposit the customer gets back, so marking it up charges for money the shop hands over later.
- Should the matrix use my cost or the jobber price?
- Your cost, meaning the number your supplier invoices you after your discount. Building a matrix off a list or jobber figure means your selling price moves whenever the catalog moves, and it hides how much of your margin came from the buying rather than the pricing.
- How often should the bands be reviewed?
- Once a year, and immediately after any supplier changes your discount level. A matrix built when a common part cost sixty dollars keeps working for a while, then the part costs ninety and it has quietly moved into the next band down on markup without anybody deciding that.