The actual width of road cycling tyres

If you buy cycling tyres with a width 25 mm this does not automatically mean they are exactly 25 mm or 25,4 mm (1 inch).

I have collected some data from my road bike.

Tyre Size Rim (inside) Pressure Width front tyre Width back tyre
Continental Grand Prix 4000S ii (folding) 25-622 17 mm 7.0 bar 27.1 mm 27.3 mm

I will update this table when more data is available.