On 2007-09-04 00:21:52 +0100, "The Medway Handyman"
said:

Am I right in assuming that when T + E cable is referred to as 2.5mm that is
the diameter of the bare conductor?

Is there a chart anywhere that gives the outside dimensions including all
the insulation?

It's the cross sectional area in square millimetres (not dia in millimetres).