Legal limit for car window tinting in uk?

Question

What is the legal limit for car windows tint in UK i have 30% so only 30% light gets through, is this a legal amount as when i went to the garage they said yes it is legal but i am sure i have heard that it is 70% or something. I do not want to get stopped by the police so could someone please answer thanks.

Answer 1

Behind the B Post (ie rear passenger windows and rear screen), there are no limits.

Side windows in front of the B Post (ie front passenger windows) must allow 70% of light through.

Front windscreens must allow 75% of light through.