Once you have the interior square footage calculated, experts say you’ll want to divide by 350. 350 square feet is the average coverage of a gallon of paint (though some say 250-400 square feet). The average coverage for a gallon of primer is 200 square feet. Your square footage divided by 350 square feet gets you the number of gallons of paint you’ll need. Square footage divided by 200 gets you the number of gallons of primer you’ll need. You can save money by ensuring you don’t buy too much paint.
Even if you think you'll probably do the job yourself, it's good preparation to seek estimates from professional exterior home painters near you. Then you'll have a financial point of comparison and you may benefit from what a home painting contractor has to say about the condition of your home, color choices and types of paint available. Let the painter make his pitch for a professional job before you decide what to do. You can still opt to do it yourself while having learned something worthwhile.

One pro tip: the term mineral spirits and paint thinner are sometimes used interchangeably. They are actually very similar. But mineral spirits are more often used indoors because they have lower fumes. Paint thinner is less expensive but has a high VOC (Volatile Organic Compounds). See Mineral Spirits vs. Paint Thinner for a complete run down on the differences between these two products.
I hired a painting company to paint my house and garage. Price was about $5,000.Sherwin Williams paint T-1000. When he was questioned about the paint peeling two days after he painted the garage he quit even with a contract not a very professional person. So,now I have to find someone else to paint my house.After 3 weeks of them trying to paint around the rain. The original time frame was 3-4 days.Yes 3 weeks and all that got done was a small two car garage that could have been done in two days.I know he did not prep correctly and properly I will end up having to redo the garage. I went to Sherwin Williams and got the colors.So beware even with a contract and good references.

Wood is probably the most time-consuming when it comes to preparing it for paint. It has to be scraped and sanded until there isn’t a single chip or bit of loose paint in sight. Any wood siding or trim with wood rot will need to be replaced, and all cracks and holes need to be filled with epoxy filler. Brush painting and roll painting wood siding costs $43 per 100 sq. ft., and spray painting costs $34 per 100 sq. ft.
Better quality paint means you will paint fewer times over the years, and you'll get better coverage when you do paint. Paint technology has improved dramatically in the past few years, with colors guaranteed to last longer than ever before. You may be tempted to skimp on paint to save money up front with a cheaper brand, but you're bound to have trouble and eventually pay more in the long run.
Keep in mind that color can impact the way a room appears in many ways. Light colors may help brighten a darker space. Cool colors will recede visually from the eye, and make a small space appear bigger. Warm colors contract visually, which can make larger spaces appear smaller or more cozy. Combining cool and warm tones in one room - like with accent walls - can visually change the shape of a room, making rectangles look more like squares. House Painting Thornton
Of course, paint brushes and rollers are also important line items on your budget sheet. A 3-inch-wide paint brush costs, on average, $10 to $20—though you'll likely need an assortment of paint brush sizes for trim, corners, and narrow surface areas. Brushes come in a variety of bristle types and qualities, and each has a different purpose. Some are intended for specific paint types, finishes, and surfaces, so be sure to buy the right brushes for your painting job.
There have been instances of unscrupulous individuals pouring inexpensive paint into expensive paint buckets and overcharging customers. Make sure you have your painting contractor write exactly what type of paint products will be used to complete the job. Also, if you specify a brand, include that and the exact shade. It may seem silly, but making sure all of this is in writing will save you from misunderstandings and unnecessary obstacles to finishing your renovation. Thornton House Painters