Auto Repair Job Estimate

About the Auto Repair Job Estimate

A written repair estimate is the document a customer judges your shop by before a single wrench turns. It has to show parts and labor separately, spell out the shop supplies fee, and land on an out-the-door number that matches the final invoice. When those figures drift apart, you either eat the difference or spend twenty minutes on the phone explaining why the ticket grew. This estimator keeps parts lines, labor, supplies, and tax in one place so the number you quote is the number you collect.

The tool is built for the reality of a service ticket: several parts at different quantities and unit costs, a block of labor priced at your door rate, a flat shop supplies charge for rags, cleaner, and fasteners, and sales tax layered on the whole subtotal. Whether you are quoting a brake job, a timing belt, or a suspension refresh, you enter the actual parts on the invoice instead of guessing a round number, which is exactly what advisors and customers both need to trust the quote.

How the Auto Repair Job Estimate works

Each part line multiplies quantity by unit cost, and those line totals are summed into a parts total. Labor is a straight multiplication of labor hours times your shop rate in dollars per hour, so 3.5 hours at $110 is $385 regardless of how the work splits across tasks. The shop supplies fee is a flat dollar amount you add rather than a percentage, which keeps it predictable on small and large tickets alike.

The subtotal is parts plus labor plus the supplies fee. Sales tax is then applied to that entire subtotal at the percentage you set, and tax plus subtotal gives the estimated total. Note that this calculator taxes the full subtotal including labor and supplies; if your state exempts labor from sales tax, quote labor on a separate untaxed line or set the rate to reflect only the taxable parts portion so you do not overcharge.

Worked example

Take a front brake job. Parts are one set of front brake pads at $65, two rotors at $48 each ($96), and one oil filter at $12, for a parts total of $173. Book 3.5 hours of labor at a $110 shop rate and labor comes to $385. Add a $25 shop supplies fee and the subtotal is $173 + $385 + $25 = $583.

Apply 8% sales tax to the $583 subtotal and tax is $46.64, giving an estimated total of $629.64. If the customer balks at the number, you can see immediately that labor is the biggest lever: trimming the job to 3.0 hours drops labor to $330 and the total to about $570.24, whereas shaving a few dollars off the oil filter barely moves the needle.

Tips & common mistakes

• Price parts at your sell price, not your cost, on this estimate. The markup lives inside the unit cost you enter here; use the Parts Markup Calculator first to set that number, then paste the sell price into each line.
• Quote labor from a flat-rate guide (Mitchell, ALLDATA, or Motor) rather than a guess. Book time is what protects you when a rusted bolt turns a 2-hour job into a 4-hour fight.
• Keep the shop supplies fee honest and disclosed. Many states cap it or require it to reflect real consumables, and a vague oversized fee is the fastest way to a chargeback or a board complaint.
• Confirm whether your jurisdiction taxes labor. In states that exempt it, taxing the full subtotal here overstates the total, so separate the labor line before you print.
• Build in a contingency conversation. Note on the estimate that additional worn parts found during teardown will be quoted for approval before installation, so the total never surprises the customer.

Auto Repair Job Estimate: frequently asked questions