Rooms are counted by how you actually use them, not by what the floor plan says. If you rebuilt one room into two, you may still book the flat as a one-room apartment — the price follows the amount of work, not the documents.
A kitchen joined with a living room counts as a room plus a kitchen: there is a cooking area with grease and a living area with dust on the surfaces. A studio is one room and a kitchen.
A walk-in wardrobe, a storage room and a loggia are not counted as separate rooms, but if they need cleaning, mention them in the comment so the cleaner plans the time.
Prices start at UAH 1,950 for a one-room flat, UAH 2,400 for two rooms and UAH 2,850 for three. Square metres matter less than you would think: two flats of the same size differ in work by exactly as many walls, doors and corners as they have.