Is 1 gallon of paint enough to paint a car?

One gallon of paint is generally not enough to paint a whole car completely with proper coverage, though it depends on car size, type of paint, application method, and whether you include primer and clearcoat. For a typical mid-size sedan, you need about 1 to 1.5 gallons of basecoat color and 1 to 1.5 gallons of clearcoat for full exterior coverage with two to three coats, plus primer if needed, so total liquid needed is 2 to 3 gallons of sprayable material. One gallon of basecoat might be enough for a small car like Miata or for exterior only with minimal coats, but coverage will be thin and you risk running short, especially if you spray door jambs, under hood, and trunk. If you use single-stage paint that combines color and clear, 1 gallon might barely cover a small car with two coats if you are efficient and use HVLP gun with good transfer efficiency, but most painters recommend 1.5 gallons for small cars and 2 gallons for larger cars and SUVs to allow for waste, overlap, and extra coats. Sprayable gallon means mixed with reducer, so one gallon unreduced makes about 1.5 gallons sprayable. So 1 gallon is not enough for full quality paint job on most cars, you need at least 1.5 to 2 gallons of color plus clearcoat, though 1 gallon could do a small car exterior with economy coverage.