You often hear me use the old carpenter's adage "measure twice, cut once" when discussing home improvement projects. That's my way of highlighting the importance of having proper measurements and calculations no matter what home improvement project you are doing. To help you with your Handyman Math, I'll explain the most common measurement terms used in the home improvement industry:

16 inches on center: This is the distance from the center of one wall stud to the center of the next stud. The studs are spaced this way to accommodate four-by-eight sheets of drywall, and it is useful to know whether you are refinishing your basement or just need to find a stud to hang pictures or other wall decorations.

Cubic yards: A cubic yard is one yard "cubed," or 27 cubic feet. It is the standard measurement used when determining the amount of concrete needed for a foundation or driveway, or for landscaping projects where you use mulch or top soil.

Slump rate: This is the calculation used to specify the exact quality of concrete you want used on your driveway. Slump is the way the amount of water in the cement mix is measured. A three-inch slump is a very stiff mix, which is very hard work for the crew to work with but gives you a stronger driveway. A six or seven-inch slump is easier on the contractor's crew, but can give you less quality.

BTU: A British Thermal Unit is the amount of heat energy needed to raise the temperature of one pound of water by one degree Fahrenheit. This is the standard measurement used to state the output of any heat-generating device like a furnace or outdoor grill.

CFM: The abbreviation means "cubic feet per minute" and is used to measure airflow in your home to calculate how many cubic feet of air pass by a stationary point in one minute. The higher the number, the more air is being forced through the ventilation system.

Roofing squares/bundles: This is how roofing companies calculate the amount of shingles they need for a roof job. A roofing square is equal to 100 square feet. So if you had a roof that was 50 feet by 50 feet, that would equal 2,500 square feet, or 25 roofing squares.

The term "bundles" indicate the amount of roofing shingles you would need for the job. Depending on the type of shingles you get, it could equate to anywhere from three bundles to five bundles of shingles per roofing square.

Square feet: One of the most common measurements used when buying flooring, paint or wallpaper is square footage. For example, carpet is measured based on the square feet of the rooms to be carpeted. Unfortunately, most carpets are manufactured in 12-foot widths. So if you have a 10-by-10-foot room to cover, you would have to buy a 12-foot-by-10-foot carpet and discard the two-foot excess.

For paint, the manufacturers indicate how many square feet a gallon will cover right on the label. But if you are painting over a very porous surface or are trying to paint a lighter color over a darker one, you may need more paint to get the results you want.

When it comes to wallpaper, Brian Eisbrenner of Shelby Paint and Decorating, www.shelbypaint.com, (586) 739-0240, said that the basic measurements still are the length and height of the wall being wallpapered. But there are some nuances that you have to take into account when ordering rolls of wallpaper that goes beyond basic square footage measurements.

"We also need to look at the type of pattern you have on the wallpaper you are ordering and determine what the pattern repeat is to decide how much wallpaper you need for a room," Eisbrenner said.

Cord of wood: If you have a wood-burning stove or fireplace at your home or cottage, you have probably purchased a few cords of wood over the years. A cord of wood is any dimension of stacked wood that will add up to 128 cubic feet. The common dimension to get a cord of wood is four feet by four feet by eight feet.

As you can see, your tape measure and calculator are just as important as any other tools in your toolbox when you start a project. Now that you've made it to the end, take a moment and read it again. That way you can read it twice, and remember it always.

If you would like to suggest a question for this column, email askglenn@masterhandyman.com. If you want to talk to Glenn Haege personally, call his “Handyman Show” on WJR-AM (760) at (866) ASK GLENN, (866) 275-4536, between noon and 2 p.m. Saturday and Sunday.