When inexperienced painters try to paint a wall, they often end up purchasing too little or too much paint. You can determine your exact paint needs by multiplying the length of a wall by its width. This will determine the total square footage of the surface and let the painter know how much paint he or she should purchase to complete the project. Unfortunately, this equation is too simple to calculate the amount of paint required to create parking lot lines. Before you purchase paint for such a project, learn the proper way to determine your paint needs, or you may end up with unnecessary overhead.
Things You'll Need
 Tape measure
 Calculator

Determine how large you want each parking space to be. Note that a typical curbside parking space is 9 by 21 feet.

Determine how much paint it will take to create the two longest lines that frame each side of a single parking space by calculating the total square feet within this area. Multiply the length you want the space to be times 4 inches.

Divide the figure from Step 2 by 12 to determine the total square feet within a single line.

Multiply the figure from Step 3 by two to determine the total square feet within the two lines that frame each side of the parking spot.

Determine how much paint it will take to create the line that frames the front of the parking space by calculating the total square feet within this area. Multiply the width you want the space to be times 4 inches.

Divide the figure from Step 5 by 12 to determine the total square feet within this line.

Add the figure from Step 4 to the one from Step 6 to determine the total square footage of painted area required to make a single parking space.

Multiply the figure from Step 7 times the total number of parking spaces you desire. Divide this final figure by 400 to determine the total number of gallons of paint required to create parking spaces within your lot.
Tips & Warnings
 If you plan to have opposing parking spaces, you only need to determine how much paint it will take to create the line that frames the front of the parking space once. In this case you should determine the square footage of the two lines that frame the sides of the parking spot and multiply this number times four. This allows you to determine the square footage for two opposing parking spots at once.
 A single gallon of paint covers 400 square feet.
 Do not use a latex or acrylic paint to create parking lines on blacktop, asphalt or concrete surfaces, or flaking will inevitably result. For lasting results, use an alkyd paint.
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