Window Tint Percentage Calculator — Mix Films

Calculate the final tint darkness when applying new film over existing glass. Don't accidentally go too dark or illegal!

Factory glass is usually 70-80%

Tint film you plan to apply

Final VLT = (Existing Glass VLT ÷ 100) × (New Film VLT ÷ 100) × 100; Factory glass is typically 70-80% VLT; Lower VLT = darker tint; 50% = light, 35% = medium, 20% = dark, 5% = limo tint
Example: 70% factory glass + 20% tint film; Final VLT: 70% × 20% = 14%; Light blocked: 86%; Appearance: Very dark - significant privacy

How do I calculate the final tint percentage when mixing films?

When you apply a new tint over existing tint, the final VLT (Visible Light Transmission) is calculated by multiplying the two percentages: Final VLT = (Existing tint VLT ÷ 100) × (New tint VLT ÷ 100) × 100. Example: 70% factory glass + 20% aftermarket film = 0.70 × 0.20 × 100 = 14% final VLT. Important: Factory glass is rarely 100% clear - most cars have 70-80% VLT from the factory. Always measure your current VLT with a tint meter before applying new film. Layering tints can quickly get you below legal limits.

What tint percentage should I choose for my car?

Tint percentage guide (VLT - Visible Light Transmission): 50%: Light tint, barely noticeable, good for sun protection, 35%: Medium tint, popular choice, moderate privacy, 20%: Dark tint, significant privacy, sporty look, 5% (limo tint): Almost opaque, maximum privacy, hardest to see through at night. Legal limits vary by state: Most states allow 35% or darker on front side windows, Many allow any darkness on rear windows, Windshield: Usually only top 4-6 inches (AS-1 line). Check your state laws - illegal tint can result in tickets and failed inspections.

Is 20% or 35% tint darker?

20% tint is darker than 35% tint. Lower VLT number = darker tint: 50% VLT = lets in 50% of light (lighter), 35% VLT = lets in 35% of light (medium), 20% VLT = lets in 20% of light (darker), 5% VLT = lets in 5% of light (darkest/limo tint). 20% tint blocks 80% of visible light vs 35% which blocks 65%. 20% is harder to see through but provides better privacy and heat rejection. 35% is easier to drive with at night and more likely to be legal. For best balance: 35% front, 20% rear.

Can I remove window tint and put new tint on?

Yes, but you must remove old tint FIRST - never layer new tint over old (it looks bad, bubbles, and gets too dark). Removal process: Heat with hair dryer/steamer (5-10 min per window), Peel from corner slowly, Remove adhesive residue with rubbing alcohol or Goo Gone, Clean glass thoroughly with ammonia-based cleaner, Let dry completely before applying new tint. DIY removal: $10-20 in supplies, takes 1-2 hours for whole car. Professional removal: $50-150. After removal, wait 24-48 hours before applying new tint to ensure glass is completely clean and dry.