Rental rates are defined as the annual rental costs for a particular space quoted on a per square foot basis. Rental rates are based on the rentable square footage of a property. They are calculated by taking the annual rental obligation of a particular space divided by the rentable square footage of that space. Rental rate totals are calculated on a weighted average of the size of the space. That is, the bigger the square footage of a particular space, the more heavily that space’s rental rate will factor into the overall rental rate calculation.