Utah tint law, explained from the driver seat

The question we hear most when someone books tint is simple: what is legal in Utah? The short answer fits on a sticky note. The longer answer matters more, because the number on the film and the number an officer reads on your window are two different numbers.

Utah tint law, window by window

The Utah Highway Patrol publishes the limits from Utah Code 41-6a-1635, in effect since May 7, 2025. Every percentage below is visible light transmission: the share of daylight that makes it through the window.

Front side windows

The driver and front passenger windows have to let in at least 35% of light. UHP allows a 5% variance when a peace officer meters the glass.

Windshield

The windshield has to let in more than 70% of light. Non transparent material is allowed in two places only: along the top edge, down to the AS-1 line or the top four inches, and in an area up to 3 by 4 inches in the lower left corner.

Rear side windows and back glass

Everything behind the driver can be any shade. The one condition is mirrors: if the rear windows are tinted, the car needs both a left and a right side mirror.

Mirrored and metallic film

Any material with a metallic or mirrored appearance is prohibited on every window, whatever its percentage.

If you have seen 43% quoted for the front doors, that is Utah's older limit. Some guides online still carry it.

Why glass and film read lower together

A 35 film lets through 35% of the light that reaches it. The film goes on glass, though, and glass on its own never passes all of the light. The two multiply.

Say your side glass passes 80% before any film. Put a 35 film on it and the window passes 35% of 80%, which is 28%. That is the number a meter sees. It sits under 35, and under the 5% variance as well.

Factory glass varies from car to car, and the only way to know what yours passes is to meter it. Try a few pairings here on a real cabin.

Two things stand out once you try it. Clear glass leaves very little room under 35 on the front doors, so the film number and the metered number drift apart fast. Behind the driver, the meter stops mattering, which is why the back half of the car is where the darker shades go.

Picking a shade for each window

A common setup is one shade on the front doors and a darker one behind. The front stays inside the law, and the rear seats, the cargo area and anything you leave in the car get the privacy and the shade.

If you carry kids in car seats, the rear doors are the windows that matter most to them, and they are the ones Utah leaves entirely up to you.

The windshield is its own decision. Most of it has to stay close to clear, so a full windshield film has to be a very light one. A sun strip across the top, down to the AS-1 line, is the other option Utah allows.

The films we install

Shade is one choice. The film is the other. We install four LLumar films on side windows and back glass, each priced for the side windows and the rear window:

• ATC, a dyed film from the LLumar retail line. From $250.
• CTX, a ceramic film and the one we install most. From $450.
• FormulaOne Pinnacle. From $650.
• FormulaOne Stratos, the top of the range. From $850.

All four block 99.5% of UV. On windshields and glass roofs we install AIR, LLumar's near clear ceramic film. The window tint page lays the four films out side by side.

Every install carries our no fault warranty: any window, any reason.

Before you book

Send us the year, make and model and how you use the car, or bring it to either studio. We will talk through a shade for each window and give you a price for your car.

Source: Utah Highway Patrol, Window Tint Requirements, effective May 7, 2025, under Utah Code 41-6a-1635.