Originally Posted by
jerry a. laska
Ah, sorry. I misunderstood your question. Your answer should be towards the bottom of
this post from the ultimate BA guide, a sticky on the BA forum.
Thanks ^
The answer from that post is
As with all awards, if you want to travel in business class, you need to multiply the miles you need by 2x, and if you want to travel in first, by 3x.
so the 3x for business class and 4x for first class shown in MileageMonkey is presumably incorrect.