How Much Paint?

[EvianBaby]

Is there any sort of rule of thumb on how much paint you need based on the size of the wall?

[rowanwitch]

yes but don't believe them.... so much depends on texture of the wall, porosity etc and I find I always use a lot more of darker colours... ask the store to hold an extra pot of paint for you or buy from someone who will let you return unopened tins just in case