I am trying to figure out how many watts per square foot I have in some of my offices using the amps and volts to the breaker box. This is commercial space so the voltages and amps are higher than resindental.

Your boxes might be 208/120 and a 3 phase 208 box. Some voltages may even be higher such as 277 for lighting and 480V 3 phase.

The problem with your calcs. Is breakers don't add up to what the main is.

You could take your main such 200 A single phase 120/208 and compute the power.

120 V * 200A * 2 or and
208 * 200; this would be lower

Outlets which would be the same as residential typically 120V and span multiple sub-spaces.