Parking Lot Capacity Calculator
Estimate roughly how many parking spaces a lot can hold from its area and stall angle. Use it for early feasibility and budgeting conversations, not for a final layout.
Area per space, adjusted for reality
Capacity is the usable area divided by the area each space consumes, including its share of drive aisle. A 90-degree stall with aisle commonly plans around 320 square feet, while angled parking uses more area per stall because the aisles and geometry are less efficient. An efficiency factor accounts for islands, odd shapes, and obstructions that pull the real count below the theoretical maximum.
What it is good for
- Sanity checking whether a site can hold the parking a use needs.
- Early budgeting, since more stalls means more paving, striping, and lighting.
- Comparing 90-degree versus angled layouts at a concept level.
Limitations
This is a conceptual planning tool only. It is not a substitute for a civil-engineered parking layout, fire access review, accessibility review, zoning analysis, drainage design, or permitting. Every one of those typically reduces the count below this estimate.
Capacity questions
How many parking spaces fit in a lot?
A common planning rule is 300 to 350 square feet per space including drive aisles for 90-degree parking, roughly 120 to 145 spaces per acre. Angled parking uses more area per space.
How many parking spaces are in an acre?
An acre is 43,560 square feet, so at about 320 square feet per space you get around 135 spaces per acre for efficient layouts, fewer after landscaping and accessible spaces.