How do you figure parking lot ratio for a building?

To calculate parking needs for a commercial building you must first find out how many parking spaces per thousand square feet of building is required per code. Let's say the code states that you will need 5 spaces for every 1,000 square feet of building. If your shopping center is 125,000 square feet you simply divide 125,000 by 1,000 and multiply by 5 to arrive at your parking needs. Example 125,000/1,000 x 5 = 625 spaces