The Locator's total desks available figure is usually the same as in the Serraview's Building & Floors tab.
Locator Example
Serraview - Buildings & Floors Example
However, the count is aggregated by the number of spaces on a floor that fall within Desk Page Container Predicate.
When a user adds desks directly from the Wireup Tool onto a floor, this will usually increase the desks available count without increasing the total in Buildings & Floors.