The main rule: 35% light transmission
In Massachusetts, the front side windows, the rear side windows and the rear window must each allow more than 35% of light to pass through (you will see this written as 35% VLT, visible light transmission). That is the number that matters when people say “legal tint” in Massachusetts.
The windshield
Only the top strip of the windshield may be tinted — above the manufacturer’s AS-1 line, or the top six inches. No tint on the rest of the windshield.
Reflective or mirrored tint
Tint also cannot be too reflective (the limit is 35% reflectance). Mirror-look films are the ones that fail.
Inspection
Tint is part of the annual Massachusetts vehicle inspection. A car with tint darker than allowed can fail, and it can also get you pulled over.
Medical exemption
People with certain medical conditions can get a waiver for darker tint through the RMV, with a physician’s certification. Keep the approved paperwork in the car.
Factory “privacy glass” vs film
Many SUVs come with darker rear glass from the factory. Adding film on top of it changes the combined light number, which is why we check before we tint.
We install tint within these limits. See window tinting in Waltham or call (781) 996-2519.