Advanced options
5% = limo, 20% = dark, 35% = medium, 50% = light
factory clear glass is about 78-80%
The law splits the car at the B-pillar: the windscreen must let in 75%+ of light and FRONT side windows 70%+ (factory glass already sits near the limit: virtually ANY added front film makes the car illegal: police carry light meters, and fail = prohibition notice, possible MOT/insurance grief): behind the driver, tint as dark as you like. That's why legitimate shops refuse front-side tint outright: a shop happy to do your fronts is a shop happy to make your car illegal. Rear tint is the whole legal product: privacy, kids-and-dogs shade, and interior fade protection.
What The Car Window Tint Calculator Works Out
- Estimated cost: the scope price plus any film upgrade. Rear screen only runs about GBP 90, full rear sets GBP 180-230 by body style and premium ceramic packages GBP 320 and up; carbon film adds about GBP 60 and ceramic GBP 120 over standard dyed film.
- The legal line: the windscreen must transmit at least 75% of light and the front side windows 70%; behind the B-pillar there is no limit. Factory glass already sits at 78-80%, so virtually any added front film is illegal, and police carry light meters.
- Worth knowing: dyed film fades purple in 3-5 years, carbon holds its colour and ceramic is the one upgrade rear-seat passengers physically feel. Factory privacy glass on SUVs is tinted glass, not film, and needs nothing.
- Film shade and bare glass (advanced): films are sold by the percentage of light they let through (5% limo, 20% dark, 35% medium, 50% light). The light through the finished window is the film percentage multiplied by the glass percentage, so 20% film on 78% glass gives about 16%.
- Would this be legal on the fronts (advanced): compares the combined figure with the 70% front side window minimum. On 78% glass only a film of about 90% or lighter passes, which is why legitimate shops refuse front-side work outright.
- Windows with old film to strip (advanced): removing failed or inherited film is about GBP 25 a window, steaming off what a previous owner's optimism applied, and is added to the all-in cost.
- Windscreen sun strip (advanced): a strip across the top of the windscreen within the legal band (above the wiper sweep, typically the top 10cm) is about GBP 40 and is the only windscreen film that stays legal.
- Cost per year (advanced): the all-in cost spread over the years you keep the car. Carbon and ceramic films are usually warranted for life; dyed film may need redoing within five years.
- Professional premium over DIY (advanced): the all-in cost minus a GBP 30-60 DIY kit. Bubbles, trapped dust and cut edges are the DIY giveaway; the professional's prepped bay, plotter-cut patterns and heat-forming skill are most of the invoice. Declare any tint to your insurer: usually free, but silence is claim risk.