Tint percentages measure Visible Light Transmission (VLT) — the share of light the film lets through the glass. A lower percentage is a darker tint: 5% blocks nearly all light, 50% barely changes the glass. 35% is the most common front-window shade; 20% and below is usually a rear-glass-only look.
Customers throw around "5 tint" and "35 window tint" like everyone knows what they mean. Your installers do — but the customer usually doesn't. Here is the plain-English version you can hand a customer, plus how to use it to land on the right shade and the right price.
What does VLT mean?
VLT stands for Visible Light Transmission — the percentage of visible light the film lets *through* the glass. It's the number behind every "window tint percentage" you've ever heard. A lower number means a darker tint (less light gets through); a higher number means a lighter tint (more light gets through).
So "35% tint" means the glass lets 35% of light through and blocks the other 65%. "5% tint" lets only 5% through — almost black. The percentage is about darkness and visibility, not about heat rejection: a light 70% ceramic can reject more heat than a near-black 5% dyed film, because heat rejection comes from the film technology, not the shade. (More on that in ceramic vs. carbon vs. dyed tint.)
One more wrinkle worth knowing: factory glass already has a VLT of its own (often around 70-80% on side windows), and the *net* VLT after film is roughly the film's rating multiplied by the glass's. That's why a "35% film" on factory glass can measure a little lower on a cop's meter — something a good shop accounts for when it quotes a legal shade.
What each tint percentage means (5%, 20%, 35%, 50%)
The most-asked shades, lightest to darkest:
- 50% tint lets half the light through. Light — mostly for heat and UV — and barely reads as tinted from outside.
- 35% tint ("35 window tint") is the most popular shade: clearly tinted but you can still see in a little. Legal for front windows in many states and the safe default for a daily driver.
- 20% tint ("limo-ish") is dark and common on rear glass. In daylight you can just make out shapes inside.
- 5% tint ("limo" or "5 tint") lets almost no light through — effectively a privacy blackout. It's often illegal on front side windows and windshields, but common on rear and SUV cargo glass where many states allow any darkness.
A quick rule of thumb for the percentages most people ask about: 35 is the everyday choice, 20 is dark-but-livable on the rear, and 5 is the blackout look that's usually rear-only and frequently illegal up front.
Window tint percentage chart (all common shades)
The full lineup shops actually sell, lightest to darkest, at a glance:
- 70% VLT — barely visible from outside. Mostly a heat/UV layer for customers who want zero look change. Common on windshields where states allow a clear or near-clear strip.
- 50% VLT — light, factory-look tint. Reads as "slightly darker glass," not "tinted car."
- 35% VLT — the everyday front-window shade. Clearly tinted, still easy to see in and out.
- 30% VLT — a shade darker than 35 without crossing into "can't see who's driving" territory. A common step-up choice on the rear when 35 feels too light.
- 20% VLT — dark. Popular rear-and-back-glass shade; you can make out shapes inside but not faces clearly.
- 15% VLT — very dark, near the edge of what most states allow anywhere on the vehicle. Rear-only in most markets.
- 5% VLT — "limo black." Effectively a privacy blackout, almost always rear-and-back-glass-only since it's illegal up front in nearly every state.
What each shade looks like — day vs. night
The conversation customers actually care about is visibility. Frame it that way:
- During the day, 35% looks darker than it really is because of the reflection on the glass.
- At night, every shade looks darker from the inside — a 20% rear window can make backing into a dark driveway feel sketchy, and 5% on a side window you actually use is rough after dark. Steer nervous drivers toward 35% up front and save 5-20% for the rear, where rearward visibility matters less.
Tell customers the law before they ask
Front-window VLT limits vary by state, and a ticket is the fastest way to a one-star review of *your* shop. A 5% front window is illegal almost everywhere; even 35% is too dark for the front in a handful of strict states. Keep your state's limit visible at the counter and quote a legal shade up front. We keep plain-English tint-law summaries — front-side VLT, rear and back-glass limits, windshield rules, and medical exemptions — by state on our regions pages. The windshield is its own special case: see the windshield tint laws, options, and cost guide for the AS-1 line and strip rules.
How to calculate your actual (net) VLT
The film's printed percentage isn't what a meter reads on the car — factory glass already blocks some light on its own, so the two multiply together. Take the film's VLT, multiply by the glass's own VLT (commonly 70-80% on side windows), and the result is roughly what a roadside meter will measure:
- 35% film on 80% glass: 0.35 × 0.80 ≈ 28% net VLT
- 35% film on 70% glass: 0.35 × 0.70 ≈ 24.5% net VLT
- 20% film on 80% glass: 0.20 × 0.80 ≈ 16% net VLT
- 5% film on 80% glass: 0.05 × 0.80 ≈ 4% net VLT
That's why a "35% film" can measure well under 35% on an officer's meter, and why quoting strictly by the film's printed number — without accounting for the glass underneath — is how a shop accidentally installs an illegal shade on a customer's car. When you're within a few points of your state's legal minimum, quote a lighter film than the limit, not right at it.
Does percentage change the price?
Usually no. A 5% film and a 35% film from the same product line generally cost the same — you're paying for the film type (dyed, carbon, ceramic) and the coverage, not the darkness. So a customer asking "how much more is it to go darker?" is almost always free to choose the shade they want within the legal limit. For the full picture of what a job costs by film tier and coverage, point car owners to how much window tint costs in 2026.
Turn the shade talk into the sale
Pair shade with film tier so the customer picks both at once: "35% ceramic up front, 20% ceramic on the rear" is a complete, confident recommendation — not a menu of confusing numbers. A kiosk-style window tint quoting flow that shows each shade and prices it instantly removes the guesswork for the installer and the customer.
The takeaway
VLT isn't complicated once you frame it as visibility, not physics. Teach it in 30 seconds — lower number, darker glass — quote a legal shade per window, and pair it with a film tier. Done that way, the percentage question becomes the start of the sale instead of a stall.