In computing the number of parking spaces required by this chapter, the following shall apply:
(a) Where floor area is designated as the standard for determining parking space requirements, floor area shall be the sum of the gross leasable horizontal area of all floors of a nonresidential building.
(b) Where seating capacity is designated as the standard for determining parking space requirements, the capacity shall mean the number of seating units installed or indicated for, each 20 lineal inches of seating facilities.
(c) Fractional numbers shall be increased to the next highest whole number.
(d) Parking space requirements for a use not specifically mentioned in this chapter shall be determined by using the most similar and restrictive parking space requirement as specified by the Planning and Zoning Commission.
(e) When the building floor area is designated as the standard for determining parking space requirements and that number is less than the minimum standard, at least one parking space shall be provided on the premises.