Your body contains two main types of cholesterol: HDL, or high-density lipoproteins, and LDL, low-density lipoproteins. If your blood has a high concentration of LDL cholesterol, you may have a greater chance of having a stroke or heart attack. Your calculated LDL cholesterol is a way for your doctor to assess your LDL level and thus your heart disease risk.
Calculating LDL Cholesterol
To find out your calculated LDL cholesterol, you will need to have a blood sample drawn after you have fasted for nine to 12 hours. Your total cholesterol, HDL cholesterol and triglycerides -- food-based fats circulating in your bloodstream -- can be determined from this sample. According to the Harvard Medical School Family Health Guide, your LDL cholesterol is calculated from these results by dividing your triglyceride level by five, then subtracting the result along with your HDL level from the total cholesterol number.
Target LDL Numbers
Your total HDL and LDL numbers are measured in milligrams of cholesterol per deciliter of blood. The calculated LDL cholesterol level associated with the fewest number of health risks is 100 milligrams per deciliter or less. A result ranging from 160 to 189 milligrams per deciliter is considered high, while a total of 190 milligrams per deciliter or more puts you at a significantly high risk of heart disease.
Importance of Lowering LDL
LDL particles -- sometimes called "bad" cholesterol -- are responsible for transporting cholesterol through your bloodstream to the parts of your body that need the fatty compound to synthesize hormones, vitamin D, digestive enzymes and cellular membranes. Your HDL, or "good" cholesterol, particles transport excess cholesterol molecules to your liver where they can be eliminated from your body. If your LDL level is too high, the HDL particles cannot remove enough and the cholesterol builds up on your artery walls. This makes the arteries narrower and stiffer, leading to cardiovascular conditions.
Ways to Control LDL
You can bring your LDL level down significantly by exercising regularly and following a diet that limits your saturated fat intake to less than 7 percent of your daily calories and your dietary cholesterol to less than 200 milligrams per day. In addition, increase your consumption of soluble fiber and plant stanols and sterols such as those in trans fat-free margarine.