Well, I've had a 24-piece encyclopaedia in mine for a long time, spread over 3 compartments and 1 book weighs 2 kg. This means that 3 shelves are each loaded with 16kg. We also had a small aquarium in there for a while, which was 30*30*30. The boards are thin, about 1cm, but stable. They lie on 4 welded-on metal plates where the board is screwed in place. So, I hope that helps you. It's a great shelf or room divider. Greetings

Per shelf I think. It's not very robust, but a shelf should hold 15kg.