Some close guesses here
The weight is a home gym im planning to put together, it will consist of:
185 kg barbell + weights
96 kg power rack
14 kg bench
2x 45 kg stable mats
Total equipment = 385 kg
Plus my own body weight of 70kg = 455 kg.
Thats an absolute worst case scenario, i cant lift anywhere near 185kg yet so a good chunk of the weights wont be on the rack. Ive asked the planning departments building control people if they have structural plans of the house, then i can see the joist spacing and thickness and maybe get a ballpark figure of how this will hold up, downstairs is an option but i would rather avoid turning half the living room into a gym.