The right emergency fund is based on risk, not a slogan.
Why the classic answer is three to six months
Three to six months of essential expenses works as a starting point because it gives many households enough cash runway to absorb job loss, repair costs, or medical surprises without turning to expensive debt.
Why the number changes by household
A dual-income household with stable jobs usually does not need the same reserve as a freelancer, sole earner, or household with volatile health or housing costs.
Bottom line
Emergency fund sizing works better when it is based on essential spending and actual risk, not copied from a generic rule without context.