Ron Joseph of the Paint and Coatings Resource Center estimates that a gallon of paint weighs roughly 10 pounds. To determine approximately how much 5 gallons of paint weighs, multiply 10 pounds by 5 to get 50 pounds of paint per 5-gallon bucket.
Gallons and pounds are different measurement systems and do not have a direct conversion system. Different types of paint have different densities, so the exact weight of 5 gallons of one type of paint may be different than the exact weight of 5 gallons of another type of paint. To determine precisely how much 5 gallons of a specific paint weighs, determine the amount of weight per gallon of that paint. Multiply the result by 5 to determine the weight of 5 gallons of paint.