What the gauge measures
A paint thickness gauge measures the total thickness of the coating on a metal panel, in microns (µm). A car's factory paint is fairly consistent from panel to panel. Repainted panels or panels with filler are thicker, and the gauge shows the difference.
What the numbers usually mean
These are rough ranges. They vary by brand, colour and panel, so compare panels on the same car rather than relying on one number.
| Reading | Usually means |
|---|---|
| About 80 to 150 µm | Original factory paint |
| About 150 to 250 µm | Likely repainted, or polished and repainted |
| 250 µm and above | Repainted with filler or body repair underneath |
| Very low reading | Over-polished paint, or a panel that has been heavily sanded |
How we test
- Measure every body panel: roof, bonnet, boot, doors, fenders, pillars and bumpers where possible.
- Take several readings per panel, not just one.
- Compare left with right and one panel with its neighbours.
- Record each panel in the report and mark the repainted ones with photos.
Limits of the test
- Plastic bumpers can't be measured by a standard magnetic gauge, so they're judged by eye and by panel gaps and colour match.
- Aluminium panels need a different type of gauge. Some modern cars have aluminium bonnets or doors.
- A repaint isn't always an accident. It can come from scratches, sun damage or a parking dent.
- Some cars come with thicker paint from the factory, so look for differences between panels.
How to use the result
A repainted bumper or door is a negotiation point. Repainted panels on both sides, a repainted roof or pillars, and signs of welding point to a bigger accident and deserve a harder look at the chassis. Our guide How to tell if a car was in an accident covers the other signs.
Questions, answered.
Can I buy a paint thickness gauge myself?
Yes, basic ones are sold online. But the readings need experience to interpret, and you still need to check panel gaps, welds and chassis.
Is a repainted car always bad?
No. A single panel repainted after a small scratch is common and affects the price a little. What matters is how many panels and whether there is structural repair.
Does every inspection include paint measurements?
Not all providers measure every panel. Ours does, and the report shows which panels were repainted.
Check the car before you pay.
We come to the car, inspect 130+ points and send you a photo report on WhatsApp within 1 hour.