So 5 litres of retail paint will cover 65 square meters (one coat), whereas 5 litres of **trade paint** would cover 85 square meters (one coat). There are approximately 2.5 square feet of surface area covered by a square meter. So, the figure of 85 square meters is equivalent to about 17 square feet.

Paint is measured in gallons or barrels. One barrel contains 42 US gallons or 39 British gallons. A gallon is defined as **4 quarts**. In other words, 1 barrel contains 21 quarts or 725.6 litres of paint.

One liter is 0.9 U.S. gallons or 0.8 British gallons. It is the most common measure of liquid volume in the world. The term "liter" comes from the kilo-liter, which is one thousand cubic centimeters. One liter has a specific gravity of 1.0003 so it weighs 100 grams per centimeter cubed. This means that if you poured a liter of water into a container that was one centimeter deep, it would only fill it half way.

Paint stores in volumes greater than **one barrel** but less than ten barrels. For example, two barrels = 10 units, three barrels = 15 units, and four barrels = 20 units.

**How much area** can 250ml of paint cover? Up to 9 m2/litre coverage. Coverage varies based on the manner and pace of application, as well as the porosity of the surface. A thin layer applied slowly will provide **greater coverage** than a thick layer applied quickly.

Coverage is the amount of surface that is covered by one coat of paint. The more coverage you get, the better. Less is usually better with latex paints because they can be very expensive. If you go over your coverage number by at least 10 percent, you'll be able to see some improvement in texture and color evenness after one dry season.

The best way to estimate **how much paint** you need is to multiply the length of the wall by the height in feet then divide by 1,000 to obtain gallons or meter squared. For example, if your wall is 8 feet long and your ceiling is 16 feet high, you would need **48 square feet** or 0.5 square meters. That's the maximum area that 1 gallon of paint will cover.

Paints vary in price depending on quality and brand. Low-quality products that are made in countries where labor laws are not stringently enforced may not have proper ventilation systems or safety measures in place during production. These factors can lead to chemical spills that can contaminate the air around them.

For **smaller surfaces**, the rule of thumb is that one US quart (0.95 L) of paint covers 100 square feet (9.3 m 2). If you'll need more than one coat of paint, double your estimate by the number of coats you'll require. For example, if you need to paint a 400 sq ft (37 m2) area twice, you'll need 2 gallons (7.6 L) of paint. 2 x 0.95 = 1.9 quarts (1.8 L), or about 2 1/4 gallons (9.1 L).

For larger surfaces, such as walls, calculate your coverage in square feet first. Then, divide the amount of paint needed by the coverage rate of an average room. For example, if you need to paint a wall 8 feet by 10 feet (2.5 m), you'd need 80 gallons (298 L) of paint. That's enough to cover 80 square feet at 2 inches (50 mm) thick. If you only use half of the space, you could get by with 60 gallons (227 L) of paint.

If you're painting **an entire house**, multiply the number of rooms by $100 and add up the totals. For example, if a house has **three bedrooms** and two bathrooms, its cost would be $300,000. You can spend between $10 and $20 per square foot for interior painting projects, so the total would be around $30,000 - $60,000.

In general, 1 litre of paint will cover 6 to 6.5 metres squared of wall. Divide the total paintable surface area by 6.5 to get how many litres of paint you will require. Most manufacturers list the volume of a container as it is used before it is refilled.

Paint is sold in **different sizes** of containers, and the amount you need will depend on the size of the canvas you want to paint. For example, if you want to paint a 2-metre by 4-meter piece of canvas, then you would need **24 litres** of paint.

You should always buy enough paint for your project, as it may not come out as planned or be limited by how much you buy. If you run out early, you can always return to the shop for more paint. It is better to have too much than not enough.

When you check out at the shop, ask them what type of container their products come in so you can choose something that will do the job and also fit into your budget. Some brands are cheaper but they may contain less paint per container.

Also, remember to include space for drying in **your calculations**. Most paints need to dry for several days before they can be worked on again.

Estimate the amount of paint needed and the area it will cover. Paint has a coverage area of 140 - 160 sq ft per litre for one coat and 70 - 80 sq ft per litre for **two coats**. In terms of square metre coverage, for new work plastering, the coverage area of paint is 8 sq m per litre for two coats, and for old work, the coverage area of paint is 13.33 sq m per litre for one coat. These figures should be used as a guide only as they vary depending on how many layers are required and the type of paint used.

The actual coverage area of any given quantity of paint depends on several factors such as the type of surface to be painted, the quality of the paint and the number of coats applied. For example, if you were painting **an interior wall** with a high-quality oil paint and it required three coats then the coverage area would be about 240 sq ft or 9.5 sq m. If you could afford the time and did not have other projects waiting for your attention then this would be a reasonable estimate of the total cost. However, if you made a mistake in your calculation and need **more paint** than you initially thought then it's easy to add more coats later. Just remember that each coat adds to the overall thickness of the material which must be removed before applying the next layer.

In general, an average-sized room can be painted with a gallon of paint every 2-3 weeks over a 2-3 month period. This is assuming there are no speed restrictions due to traffic or pedestrians and that you do not rush through the job.