AqAdvisor is a really good resource, especially for new aquarium-owners...but it itsn't the be-all, end-all of aquarium management. If new to tanks, staying under 100% is recommended since things won't spiral out of control as fast.

AqAdvisor takes into account fish adult size, estimated bioload (skinny vs fat-bodied fish), some species interactions (predation or schooling needs), and swimming area requirements (active vs. sedate fish).

But it doesn't assess whether you're using a barren fish-only tank, decorated tank, light/med/heavily planted tank, or the types of visual barriers and available swimming space. It also doesn't really take into account how many top/middle/bottom dwelling fish you have - if all your species hang out in the same area, your tank would be more 'full' in a social aspect than if they tended to keep to different areas of the tank. Those all have an effect on stocking.

I'd say to stay under about 150%, personally...for ease of care and feeling like nothing's over-crowded. Other people may keep higher stock loads - they just need to be more careful about crowding, stress, disease, and water quality.

If you want to stock more, add just a few fish at a time, and keep an eye on water quality and fish interactions to make sure your tank stays stable and none of the fish are acting stressed.