Auto Repair Estimate Calculator
Build a parts-and-labor estimate line by line and print it as a customer copy.
OpenSHOP SUPPLIES FEE CALCULATOR
Rags, brake cleaner, gloves, thread locker, the parts washer, waste-oil disposal. Real costs, too small to itemise, and the reason the shop-supplies line exists. It is also the line customers challenge most often, because plenty of shops charge it with no method behind it. Set a method here.
SHOP SUPPLIES
Per repair order
Set the method, then check the result against what is defensible.
| Line | Amount |
|---|---|
| Computed before the cap | $24.36 |
| Cap applied | no |
| Share of labor | 6.0% |
Printed on the invoice as
Shop supplies
Fee charged
$24.36
What the fee is supposed to cover
Solvents and cleaners, small quantities of fluid, rags and their laundering, servicing the parts washer, and the disposal of used oil, coolant and other regulated waste. What ties them together is that metering them per job would cost more than the consumable. That is the honest argument for a blanket fee, and it is a good one.
Percentage of labor, with a cap
The common convention is 5–10% of labor, capped at $30–$50 per repair order. Labor is the right basis because consumable use tracks hours in the bay, not the price of the part being fitted. A $2,400 catalytic converter uses no more brake cleaner than a $200 one.
The cap is what keeps the fee honest on a long job. Without it, a 12-hour engine job carries a $100 supplies line that no reasonable accounting supports.
The rules vary by state
Some states restrict the fee to actual cost with no markup; some require it to be disclosed in writing before authorisation; some require every charge on a repair invoice to be itemised, which means a bare “shop fee” line is not compliant. Louisiana statute RS 32:1263, cited below, is one example of the kind of rule that exists. Check your own state before you set the percentage, and put the disclosure on the repair order where the signature is.
Where it lands on the paperwork
The estimate calculator applies the same percentage-with-a-cap logic, so a customer who compares the estimate against the invoice sees the same number twice — which is the point. If the fee is doing real work in your margin rather than covering real consumables, that is a door-rate problem wearing a disguise.
WHAT IS DEFENSIBLE
- Common convention
- 5–10% of labor, capped at $30–$50 per repair order
- Above 10% or uncapped
- expect to be challenged
- Basis
- labor, not the invoice total
- Never
- a consumable already on the parts list
- Disclosure
- itemised, named, before authorisation
RELATED
Auto Repair Invoice Template
A fillable invoice sheet with vehicle block, line items, totals and warranty terms.
OpenRepair Order Template
Complaint, cause and correction on one authorised sheet with a signature line.
OpenSOURCES
Each line is where a figure on this page came from and the date it was read.
| Figure | Source | Read |
|---|---|---|
| Percentage-of-labor convention and the cap band | Car Talk — Are shop supplies a legit charge? | |
| Door rate behind the seeded labor figure | Tekmetric — Average Auto Repair Labor Rates by State | |
| Parts margin, for the double-billing comparison | AutoLeap — Auto Parts Markup Chart | |
| State-level disclosure and itemisation requirements exist and differ | Louisiana RS 32:1263 (an example statute) |