Hight of back boxes for central heating drops

[Fallout]

What height do people tend to set back boxes at when first fixing central heating for 10mm plastic microbore. The radiator would be positioned an inch or 2 above the skirting board. (5 inch skirts). Thanks

 

[Fallout]

Or what height do you tend to place them in relation to the bottom of the radiator? Say 150mm from the bottom of the radiator to bottom of the back box?

 

[Dangee]

Approximately 450mm.

 

[Dangee]

From the floor