Before starting a home-improvement project, there's some math to brush up on. (Metro Creative Connection)

Math may not have been your favorite subject in school, but like it or not it's a part of just about every home improvement project.

You might be trying to figure out how many square feet are in a room so you can buy the right amount of paint or flooring, or maybe you're doing something a bit more complicated, like calculating a room's volume for sizing a bath fan, or figuring out the number of board feet in a piece of lumber.

But don't let your eyes glaze over just yet, because all you need to handle all this and more is a basic calculator and a few simple formulas.

Area calculations take two of the three dimensions into account. It might be width and length, as when measuring a floor, or width and height, as when measuring a wall. For the following examples, we'll use a rectangular room that is 10 feet wide, 12 feet long, and 8 feet high.

• Area of the floor or ceiling: Multiply the length by the width (10 feet x 12 feet = 120 square feet of area).

• Area of a wall: Multiply the width of the wall by its height. So one of the walls is 80 square feet (10 feet wide x 8 feet high) and the other is 96 square feet (12 feet x 8 feet). If you need the total square footage of the walls - for figuring paint or wallpaper for example - you can simplify the calculation by first adding all the wall lengths together, then multiplying by the height (10 + 12 + 10 + 12 = 44 x 8 = 352 square feet of total wall area).

• Area in square yards: There are 3 feet in a yard, so there are a total of 9 square feet in a square yard (3 x 3). To calculate the number of square yards in our example room, which you might want to do when ordering carpet, divide the total square footage of the floor by 9 (120 square feet / 9 = 13.33 square yards).

•Area in square inches: There are 12 inches in a foot, so there are 144 square inches in a square foot (12 x 12). To convert an area from square feet into square inches, simply multiply by 144. (Our room has 17,280 square inches).

•Area of a triangle: If you want to figure out the area of a triangular space, such as a gable end, you need a simple formula: 1/2 x base x height. This means you multiply .5 x the base of the triangle x the height of the triangle. So, if your gable end is 18 feet wide at the base and 6 feet high from the base to the peak, it contains 54 square feet (.5 x 18 feet x 6 feet = 54 square feet).

•Area of a circle: The formula for this is: pi x radius2 (pi = 3.1416). Let's say you have a circular space that's 22 feet across. That distance across is the diameter, and half of that, or 11 feet, is the radius. So the calculation would be : (3.1416 x 11 x 11 = 380.13 square feet).

•Circumference of a circle: The circumference of a circle is the total distance around it, which is often a handy thing to be able to calculate. To do that, you need this formula: pi x diameter. For our 22-foot diameter circle, the circumference would be 69.12 feet (3.1416 x 22).

Where area measurements were two-dimensional, cubic measurements take all three dimensions into consideration. This will tell you the volume of a given area, for anything from sizing a fan to ordering concrete for a foundation.

•Volume of a room: For the volume in cubic feet of our example room from above, simply multiply the width by the length by the height: (10 feet x 12 feet x 8 feet = 960 cubic feet).

•Volume in cubic yards: There are 27 cubic feet in a cubic yard (3 x 3 x 3). So if you would like to convert cubic feet into cubic yards, which is necessary when ordering dirt, gravel, and concrete, simply divide the number of cubic feet by 27. For example, if you have a foundation form that is 2 feet wide, 20 feet long, and 1-1/2 feet high, first figure the cubic feet, then convert to cubic yards: (2 feet x 20 feet x 1.5 feet = 60 cubic feet / 27 = 2.22 cubic yards).

•Volume in cubic inches: There are 1,728 cubic inches in a cubic foot (12 x 12 x 12). To convert the cubic feet in the above example into cubic inches, you would multiply by 1,728 (60 cubic feet x 1,728 = 103,680 cubic inches).

Many types of lumber are sold by the board foot. This unique unit of measurement refers to a board that's 1 foot long, 1 foot wide, and 1 inch thick. Any time you would like to know how many board feet are in a given piece of lumber, use the following formula: T x W x L / 12, where T = the thickness of the board in inches, W = the width of the board in inches, and L = the length of the board in feet.

For example, suppose you had a piece of 2 x 8 lumber that was 16 feet long. Using the formula, you can determine that the board contains 21.33 board feet (2 inches x 8 inches x 16 feet / 12 = 21.33).

Have a home repair or remodeling question for Paul? He can be reached by email at improvingyourhome@ykwc.net.