Window tint is sold by percentage, and the numbers run backwards from what most people expect. A lower number is a darker tint. Here is what the percentage actually measures, which shades people choose, and why the number tells you nothing about heat.
Key takeaway: the percentage is how much visible light gets through. Heat rejection is a separate spec, and it depends on the film type, not the shade.
What does tint percentage mean?
The percentage is VLT, or visible light transmission: the share of visible light that passes through the glass and film together. A 35% tint lets 35% of the light through and blocks the rest. A 5% tint lets only 5% through, which is why it is called limo tint.
Factory glass is not perfectly clear, so the finished window is always a little darker than the film's number alone. Police and inspectors measure the whole window, not the film. We explain how in how police measure window tint.
What do the common shades look like?
- 70%: barely visible. Often used on front windows and windshields where the law is strict.
- 50%: a light smoke that still looks clean and keeps night visibility easy.
- 35%: a classic factory-plus look. You see tint, and you still see in.
- 20%: dark, with real privacy. Common on rear windows.
- 5%: very dark. Great privacy, but it takes getting used to at night.
Does a darker tint block more heat?
Not by itself. Heat comes mostly through infrared light, which you cannot see. A quality ceramic film can reject far more heat than a cheap dyed film that looks twice as dark. That is why we always talk about the film first and the shade second. See ceramic vs carbon vs dyed tint and does window tint reduce heat.
Which percentage is legal?
It depends on the state and the window. Delaware, Pennsylvania, Maryland and New Jersey all have different rules for front, rear and windshield glass, so check ours before you pick: Delaware, Pennsylvania, Maryland and New Jersey.
Is 5% tint legal on the front windows?
Not in our four nearby states. Front-window limits are lighter. Check the state guide for your car's registration.
What is the most popular tint percentage?
For rear windows, 20% and 35% are the most common. For front windows, it depends on the state limit.
Can I get different percentages on different windows?
Yes. Many drivers go lighter on the front doors and darker on the back.
Sources
- International Window Film Association, window film basics
- U.S. Department of Energy, window films and heat