I’ve been at two events recently in which the presenters used maddeningly small fonts and it reminded me that I did a small project in April 2012 to try and fight this at my local university.

With a friend, we measured every single lecture hall on campus (although they have built several since) and worked out the minimum acceptable font size for slides.

We benchmarked this with the UK driving licence. As in, we assumed that a student could read a numberplate at 20m and did the maths that worked out the equivalent font size for each lecture hall in the university.

You can read the (old, badly written) methodology here, and see the font sizes for the rooms themselves here