Again, haircuts don't often require the same upkeep that regular colour does, however, short cuts are still an investment. If you want to keep your hair in healthy condition and keep your bob looking fresh, regular cuts every six weeks are recommended. "Longer bobs and curly hair can get away with longer, approximately six to eight weeks," said Windle. But those with shorter or finer hair, you could be looking at every four to five weeks to keep it in perfect condition.