How to calculate HDL to LDL ratio

Updated April 17, 2017

According to health professionals---including the American Heart Association---high cholesterol often leads to heart attack and/or stroke. However, the true risk of your cholesterol level is often quite difficult to calculate. While low-density lipoprotein cholesterol (LDL) will clog your arteries over time, high-density lipoprotein cholesterol (HDL) actually protects you against heart attack and stroke. Thus, you will want a low LDL and a high HDL. One of the best indicators of true risk is the ratio of HDL to LDL cholesterol. To calculate your ratio and evaluate your risk, all you need is a complete lipid profile that will measure both LDL and HDL.

Ask your doctor for a cholesterol test that will yield an entire lipid profile. Usually you can call into your doctor's office and request one rather than file a request in person. Some doctors administer the test in the office and others will refer you to a lab for testing.

Fast for at least 12 hours before your test. You can drink water or black coffee but other foods will adversely affect the test's accuracy.

Visit your doctor's office or testing facility for your cholesterol tests. During your test, a nurse will take a vial of blood. Lab technicians will interpret the results and send their findings to your doctor.

Wait for the results of your cholesterol test. After about a week, you will receive the results in the mail. Sometimes your doctor will already indicate the HDL to LDL ratio. If not, look at your HDL number and your LDL number and place the HDL over the LDL. For instance, if the HDL number is 50 and your LDL number is 180, then your ratio is 50 to 180, which simplifies to 5 to 18 or a little over 1 to 4. The ratio will then simplify further based on your LDL number (in this case 4).

Interpret your results. According to the Yale-New Haven hospital, any ratio more than 1 HDL to 5.1 LDL (a 5.1 ratio) is considered "dangerous." A maximum heart protection ratio on the other hand is 3.5 or less. Any ratio between those two is considered "average."


If your ratio is high, talk to your doctor about how to increase your HDL levels through exercise and diet.


For the most accurate ratio reading, ask your doctor to calculate it. While doctors will usually correctly report your lipid profile to you, handwriting errors are always possible. Thus, ask your doctor directly about the cholesterol test findings and your overall cholesterol ratio.

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About the Author

Alexander Grouch is a freelance screenwriter, journalist and children's book author. He currently writes music reviews for "The Red Alert." Grouch has visited all 48 contiguous states and plans to document his journeys in a travelogue. He earned a Bachelor of Arts in Africana studies from Brown University.