Said Hufflepuff, "I'll teach the lot,
And treat them just the same.

You might belong in Hufflepuff,
Where they are just and loyal,
Those patient Hufflepuffs are true,
And unafraid of toil.

You might belong in Gryffindor,
Where dwell the brave at heart,
Their daring, nerve, and chivalry,
Set Gryffindors apart;
You might belong in Hufflepuff,
Where they are just and loyal,
Those patient Hufflepuffs are true,
And unafraid of toil;
Or yet in wise old Ravenclaw,
If you've a ready mind,
Where those of wit and learning,
Will always find their kind;
Or perhaps in Slytherin,
You'll make your real friends,
These cunning folks use any means
To achieve their ends.

I think you could ask 10 English people the same question about class and get a very different answer.

Hufflepuffs are particularly good finders!

There's no formula.