If you have a steady hand, a good work ethic and need to earn some extra income, you may want to try painting houses. Besides being a good painter, and paying attention to detail, you will need to know what to charge for the jobs you do. Rates and formulas vary, depending on whether you are painting the interior or exterior of a home. Your charges will include labour, supplies, ceiling height and the size of the surface to be painted.

Determine the square footage of the area to be painted. Measure and multiply the width of each wall by the height and include the ceiling. Add those numbers. (Example: If Wall No. 1 is 10 feet high by 10 feet wide, Wall No. 2 is 12 feet by 10 feet, Wall No. 3 is 10 by 10 and Wall No. 4 is 12 by 10, you will have 420 square feet to paint. Be sure to count every flat surface to be painted and estimate more if the ceiling is vaulted.

Consider the height of the room. In rooms with high ceilings, measure the upper portion of the room separately, because you should charge more for areas you need to paint from a ladder. If a room is 10 by 12, but has 12-foot ceilings, calculate the 288 square feet below the 8-foot line separately from the remaining 176 square feet, which are above the 8-foot line.

Decide what your standard square-foot rate will be. Depending on your experience and the going rate in the area where you live, charge between 90p and £2.20 per square foot. Base your square-foot rate on how much you want to make per hour and how fast you can complete the job. For instance, if you want to make £65 per hour and you can paint a 10-by-12 room with 10-foot ceilings in 5 hours, you'll want to make at least £325 in 5 hours. If the room has 420 square feet, you will charge 70p per square foot. If you think that is low, it is. You aren't done calculating.

Determine the cost of your materials and incidentals. They include transportation, a ladder or other equipment rentals, paint (if you are paying for it), tape, tarps and paint brushes. Add the cost of all the items and divide by the number of square feet you are painting. For example, if you are painting 420 square feet and your materials cost £136, you can safely add 50 cents to your square-foot price.

Based on the examples, if your room is 420 square feet and your per-hour labour cost is 70p and your materials cost about 50 cents per square foot, you can charge £1.40 per square foot--or £461.3 to paint the room.

#### Tip

Know in advance how long it generally will take you to paint a room. You may want to practice on a room in your house. Take into account that you will paint a room faster if it is empty, and slower if you have to move or work around furniture. Use a similar method to determine how much to charge to paint the outside of a house. Remember there will be more prep work involved and you will be on a ladder much of the time.