i use this as guideline Guideline

my ultimate purpose is to be able to escape from the house soonest possible . if a 3 x 1kg FE + 6kg FE also cant extinguish the fire , it should be a very big fire , so i will just escape only....

6kg and 9kg FE is almost the same , if a 6kg FE can't do the job , so do 9kg ...

For my case, 9/10kg is not easily wieldable by the petite ladies in my household. So I skip those, easier to have more smaller ones then 1 super huge when ppl cant use it.

Its more important to get the right kind of FE, what works in the kitchen might not work at your fuse panel etc.