In the US it's 10% if you withdraw before retirement age. Which is currently 59.5 Which can be legislated to be changed (has been brought up before) to be later. which is a worry/attack vector IMO.
Discussion
probably too late now, but you could also look into the rule of 72(t) to skip the 10% penalty II
you commit to do 5 years of substantially equal payment plan (SEPP).
That is what helped me retire early (I'm 56 and in my 2nd year of 5 years).