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Diagnostics · Free tool

Free Repair Cost Estimator

Enter the parts, the labor hours and the shop’s hourly rate. The estimator totals the repair, shows what doing it yourself would save and compares it with the national average.

  • Free to use
  • No signup
  • Runs in your browser

The quote

$

The parts total on the estimate.

hours

The time the shop is billing.

$per hour

AAA: almost half of shops charge $120 to $159 an hour.

$

A basic diagnostic test starts at about $40.

$
%

Compare with the national average

Averages for parts and labor: CarMD, repairs recommended in 2025.

Estimated repair cost

$390

1.5 hours at $140 an hour, plus parts.

Parts
$180
Labor
$210
Tax and fees
$0
Do it yourself (parts only)
$180
Labor you would save
$210
Range at $100 to $200 an hour
$330–$480
  • Parts$180
  • Labor$210
  • Tax and fees$0

An estimate from your own figures. Parts prices and labor times vary by vehicle, so ask for a written quote.

An estimate from the figures you enter, not a quote. Read the disclaimer. Updated .

02Your result

What your repair cost estimate means

A repair bill is parts plus labor plus a few small extras. Seeing them apart is how you judge a quote.

  1. 01

    Estimated repair cost

    Parts, labor, tax and fees added together. Compare it with the written quote line by line.

  2. 02

    The labor share

    Hours multiplied by the shop’s rate. It is usually the part that differs most between shops.

  3. 03

    The DIY figure

    What the job costs in parts alone. The gap is what you pay for someone else’s time, tools and warranty.

What to do next

03How it works

The repair cost formula

Every repair estimate is built the same way, whatever the job.

Repair cost
Cost = parts + (hours × rate) + tax + fees

Repair cost = parts + (labor hours × shop rate) + sales tax on parts + diagnostic and shop fees

DIY cost = parts + sales tax. The saving is everything else.

What each term means

parts
The price of the parts on the estimate, before tax.
hours
The labor time the shop bills for the job, not the time the car spends there.
rate
The shop’s hourly labor rate.
tax
Sales tax, charged here on the parts.
fees
A diagnostic fee, shop supplies and disposal charges, where the shop adds them.

What the tool assumes

  • You supply the parts price and labor hours, ideally from a written quote.
  • Sales tax is applied to parts only. Some states also tax labor.
  • The national averages are CarMD’s modeled figures for parts and labor on check engine repairs.
  • DIY cost leaves out tools you may need to buy and the value of your time.

04Worked example

Repair cost example: 1.5 hours of labor and $180 in parts

A repair quoted at $180 in parts and 1.5 hours of labor, at a shop charging $140 an hour.

  1. 01

    Work out the labor

    1.5 hours × $140

    $210

  2. 02

    Add the parts

    $210 + $180

    $390

  3. 03

    Find the DIY cost

    Parts only

    $180

  4. 04

    Find the saving

    $390 − $180

    $210

  5. 05

    Test other shop rates

    1.5 hours at $100 and at $200 an hour

    $330–$480

Estimated repair cost

$390

The same job would cost $330 at $100 an hour and $480 at $200, which is why a second quote is worth getting.

Try your own numbers

05Background

What car repairs cost, and why quotes differ

Labor rates explain most of the difference between two quotes for the same job. AAA reports that mechanic labor rates run from less than $100 to more than $200 an hour across the country, and that almost half of repair shops charge between $120 and $159.

Average check engine light repair, 2025
$554
of that average was parts
$332
of that average was labor
$222
The ten most common check engine light repairs and their average cost
RepairAverage costShare of repairs
Catalytic converter$1,5117.4%
Oxygen sensor$2876.7%
Ignition coils and spark plugs$4806.0%
Mass air flow sensor$3465.8%
Ignition coils$2565.0%
EVAP purge control valve$1724.9%
Fuel injectors$5722.8%
ABS wheel speed sensor$3142.7%
Thermostat$3242.4%
Spark plugs$2991.8%
CarMD 2026 Vehicle Health Index, based on repairs recommended in 2025. Modeled national averages for parts and labor, so your quote will differ.

Before paying for a diagnosis, know what it should cost. A basic diagnostic test starts at about $40, and a mechanic or dealer will usually charge around an hour of labor to find a fault. See DIY or mechanic for which of these jobs are realistic at home.

Dimly lit auto workshop with tool chests and equipment lining the walls

06When to use it

When to use a repair cost estimator

Before you say yes to a quote, and before you decide a job is worth doing yourself.

  • To check a quote

    Rebuild the estimate from its own parts and labor figures and see whether it adds up.

  • To compare two shops

    Hold the parts and hours steady and change only the labor rate.

  • DIY or pay

    See how much of the bill is labor, which is what doing it yourself saves.

  • To plan for a repair

    Use the national averages to set money aside before the quote arrives.

Mistakes to avoid.

  • Comparing totals without checking that both quotes are for the same parts and the same work.
  • Confusing labor hours billed with the hours the car spends at the shop.
  • Approving a repair for a code without asking whether the cheaper causes were ruled out.
  • Counting only parts for a DIY job and forgetting the tools it needs.

07Related guides and tools

Keep going from here.

Part of our OBD2 Codes guide

Guides that go with this tool

Related tools

All free tools

08Questions

Repair Cost Estimator: your questions.

How do I estimate a car repair cost?

Add the parts to the labor, where labor is the hours billed multiplied by the shop’s hourly rate, then add tax and any fees. A job with $180 in parts and 1.5 hours at $140 an hour comes to $390 before tax.

What is the average mechanic labor rate?

It varies widely. AAA reports rates from less than $100 to more than $200 an hour across the country, with almost half of repair shops charging between $120 and $159 an hour.

How much does a check engine light repair cost?

The average was $554 in 2025, made up of $332 in parts and $222 in labor, according to CarMD. The range runs from $172 for an EVAP purge valve to $1,511 for a catalytic converter.

How much does a diagnostic test cost?

A basic diagnostic test starts at about $40, and a mechanic or dealer will usually charge around an hour of labor to find a fault. Many auto parts retailers will read a stored code for free.

Is it cheaper to fix a car yourself?

You save the labor, which was about 40% of the average check engine light repair bill in 2025. Set that against the tools you need, the time it takes and whether the job is safe to do at home.

09Estimates and sources

Read this before you rely on it.

Built and checked by CarTipsMentor Team. Last updated . How we check our work.

Sources

  1. [1]CarMD, 2026 Vehicle Health Index (calendar-year 2025 repair data)
  2. [2]AAA Automotive, Average Mechanic Labor Rate: Repair Costs in Your State 2026
  3. [3]J.D. Power, What Is a Car Diagnostic Test?
  4. [4]Edmunds, What Your Check Engine Light Is Telling You