Plate loader
Plates go on in pairs, so most weights cannot be loaded at all. This rounds down to the closest one that can be, shows the stack heaviest first, and tells you how far under the number you asked for it landed.
Per side
Example40kg
100 kg on the bar, exactly what you asked for.
Heaviest first, which is how a bar is loaded. This is not claimed to be the fewest plates: what is claimed, and what the test checks over the whole range, is that the stack comes to 40 kg a side exactly, so the bar plus both sides is 100 kg.
Unit
Nothing is converted. Switching the unit switches the bar and the rack, because a gym has one or the other.
Bar
Plates on the rack
Unlimited pairs of whatever is ticked. How many of each the gym owns is deliberately not modelled: it makes most targets unreachable for reasons you cannot see, and running out of 20s is a problem you solve by looking at the rack.
Nothing here is stored. The numbers stay in this browser.