Parking Lot Size Calculator

A parking lot needs roughly 300 to 350 square feet per space once you include the drive aisles. Use the calculator below to see how much land your parking spaces need, or how many parking spaces fit on a lot of a given size.

Not sure how many spaces you need? The parking ratio calculator works out required spaces from your building area and your zoning code's parking ratio.

How many square feet is a parking space?

A standard parking stall is about 9 feet wide by 18 feet long, or 162 square feet. Compact stalls are smaller, often around 8 by 16 feet, and accessible stalls are wider because they need an access aisle next to them.

The stall is only part of the space a car takes up. Every stall needs a drive aisle in front of it, and a two-way aisle for 90 degree parking is usually about 24 feet wide. Split that aisle between the stalls on both sides, add curbs and corners, and each space takes about 300 to 350 square feet of the lot.

How to calculate parking lot size

1. Decide how many spaces you need. Your zoning code sets the minimum.
2. Pick a square footage per space that includes aisles. 325 square feet is a reasonable starting point.
3. Multiply the spaces by the square feet per space.
4. Divide by 43,560 to convert square feet to acres.

How many parking spaces per acre?

An acre is 43,560 square feet. At 300 to 350 square feet per space, an acre of surface parking holds roughly 125 to 145 spaces. A long rectangular lot with straight rows packs in the most cars. An irregular lot, a lot with landscaped islands, or one with angled parking holds fewer.

What changes the size of a parking lot?

• Parking angle. 90 degree parking is the most efficient. Angled parking uses narrower one-way aisles but fits fewer cars per row.
• Stall and aisle sizes. Your local code sets the minimum stall dimensions and aisle widths.
• Accessible spaces. Federal ADA rules require a share of accessible stalls, which are wider.
• Landscaping and setbacks. Many codes require landscaped islands, perimeter buffers and setbacks that take land away from parking.
• Lot shape. Narrow or irregular lots waste space at the ends of rows.

Parking also counts against how much of a site you can build on. Check your lot coverage and floor area ratio limits, and look up your city's zoning code for the exact parking design standards. The Wikipedia article on parking lots covers layout types in more detail.

Frequently asked questions

How many square feet is a parking space?

A standard parking stall is about 9 feet wide and 18 feet long, which is 162 square feet. Once you add the drive aisles needed to reach each stall, a parking lot usually needs about 300 to 350 square feet per space.

How many parking spaces fit in an acre?

Roughly 125 to 145 spaces. An acre is 43,560 square feet, and at 300 to 350 square feet per space including aisles, that works out to about 125 to 145 spaces. Landscaping, curbs and odd lot shapes usually bring the real number lower.

How big does a parking lot for 100 cars need to be?

About 32,500 square feet, or roughly three quarters of an acre, using 325 square feet per space including drive aisles. A tight, efficient layout needs less, and a lot with wide aisles, islands and landscaping needs more.

Does the local code change the parking lot size?

Yes. Local zoning codes set minimum stall sizes, aisle widths, accessible spaces and landscaping requirements, and those change how much land each space takes. Use this calculator for early planning, then check the parking section of your local code.