How old is a late bloomer?

Late bloomers are usually 40-50 years old.

There is no fixed age for a late bloomer, which generally refers to 40-50 years old. Being a late bloomer is an idiom, which originally meant being overqualified and taking a long time to make a vessel. Later, it was used to mean that people who can undertake great things or make great achievements are late. Act as predicate, object and attribute in a sentence.