Window tint percentages, explained

VLT stands for visible light transmission. A 20% film lets through 20% of the visible light that hits it and blocks the other 80%. The scale isn't linear to the eye: going from 70% to 50% is subtle, while going from 20% to 5% takes a window from dark to black. That is why the visualiser above darkens the glass on a curve rather than in equal steps.

Night view is for the film on typical clear glass. It is a general guide; eyesight, roads and lighting vary.

Car glass isn't perfectly clear. Factory clear glass typically lets through about 70–85% of light, and the privacy glass fitted behind the front doors on many SUVs, estates and vans lets through about 15–30%. Film adds to that, and the two multiply: film VLT × glass VLT = what gets through.

• 35% film on clear glass (≈80%)

  ≈ 28%

  35% × 80% = 28%

• 20% film on clear glass (≈80%)

  ≈ 16%

  20% × 80% = 16%

• 35% film on privacy glass (≈20%)

  ≈ 7%

  35% × 20% = 7%

Two things follow. A tint meter reads lower than the number on the film box, so ask your installer what the window will measure, not just which film it is. And film on privacy glass gets very dark very quickly: 35% film on 20% privacy glass lets through about 7%, not far off 5% film on clear glass at about 4%.

In Great Britain, for vehicles first used on or after 1 April 1985, the windscreen must let at least 75% of light through and the front side windows at least 70%. There are no rules for tinting the rear side windows or the rear windscreen. For vehicles first used before 1 April 1985, the windscreen and front side windows must both let through at least 70%.

The limit applies to the window as a whole, glass and film together. Because factory glass already blocks some light, almost any film is likely to take a front side window below 70%. The police and DVSA examiners use light meters, and windows that are too dark can lead to a prohibition notice stopping you using the vehicle until the tint is removed, a penalty notice or a court summons. Source: GOV.UK, tinted vehicle windows: the law.

There is no single US limit. Each state sets its own rules, usually with separate limits for the windscreen strip, front side windows, rear side windows and rear window, and some states treat sedans differently from SUVs, vans and trucks. Rules on reflective film and medical exemptions vary too. Check your state's DMV or the statute itself before you book, and remember that the limit usually applies to the glass and film together.

The comparisons people search for most, each with the same car side by side at both shades and the numbers behind them.

• 5% vs 15% tintBoth are privacy shades. 15% keeps most of the look and is easier to see out of at night.
• 5% vs 20% tint20% is the more common choice for people who want dark windows but drive at night.
• 5% vs 35% tintThis is a choice between a blacked-out look and a medium, see-through tint. Many owners use both: 5% at the back, lighter at the front where the law allows.
• 15% vs 20% tintThese look very similar from outside. 20% is slightly easier to see out of at night; 15% is slightly more private.
• 15% vs 35% tint15% is for privacy; 35% is for looks and comfort with little loss of visibility.
• 20% vs 25% tintA small step. 25% gives a touch more night visibility and still hides most of the cabin by day.
• 20% vs 30% tint30% trades some privacy for an easier view out after dark.
• 20% vs 35% tintThe most searched pair. 20% hides the cabin by day; 35% looks tinted but lets people see in, and is easier at night.
• 25% vs 35% tintBoth are medium shades. 25% gives more privacy; 35% gives more light at night.
• 30% vs 35% tintHard to tell apart on the car. Choose on night visibility (35%) or a little more privacy (30%).
• 30% vs 50% tint30% looks clearly tinted; 50% is mainly about glare and heat.
• 35% vs 50% tint35% is the lightest shade that reads as tinted. 50% is subtle and mostly about comfort.
• 35% vs 70% tint35% changes the look; 70% is nearly invisible and only worth it with a heat-rejecting film.
• 50% vs 70% tintBoth are comfort films rather than a look. 70% is closer to clear; 50% cuts more glare.

The window tint visualizer lets you set front and rear shades separately and switch between clear and privacy glass. To see tint on your own car, the tint preview renders it onto a photo you upload.