Normally you need a similar ammount of mtr2 of Thermowarm panels as Thermowarm mats.

You would work out in a similar way that the total amount of mats required is equated.

Each Thermowarm 1200 x 600mm panel covers 0.72mtr2.

So for the conservatory floor example used before for an area of 9mtr2 a 10% wastage is added bringing the total to 9.9mtr2 divid this by 0.72 mtr2 this comes to 13.75 panels. You would round that up to 14 panels required.