LDL Calculator

Low-density lipoprotein cholesterol, or LDL-C, is commonly used to assess atherosclerotic cardiovascular risk and guide lipid-lowering treatment. Many routine laboratory reports estimate LDL rather than measuring it directly. The classic Friedewald equation subtracts HDL cholesterol and an estimate of very-low-density lipoprotein cholesterol from total cholesterol. In conventional mg/dL units, that estimate is triglycerides divided by five. This calculator also reports non-HDL cholesterol, which is total cholesterol minus HDL cholesterol. For example, total cholesterol of 200 mg/dL, HDL of 50 mg/dL, and triglycerides of 150 mg/dL produce an estimated LDL-C of 120 mg/dL. The arithmetic is straightforward, but interpretation is individualized. Desired LDL levels depend on established cardiovascular disease, diabetes, kidney disease, familial hypercholesterolemia, age, smoking, blood pressure, overall estimated risk, and the treatment guideline used by the clinician. The Friedewald equation has important limitations. It is not considered reliable when triglycerides are 400 mg/dL or higher, and accuracy may decline at lower LDL levels or with elevated triglycerides. Whether fasting is required depends on the clinical situation and local practice. Newer equations such as Martin-Hopkins and Sampson may perform better in some ranges, and direct LDL measurement may be ordered when calculation is unsuitable. Results from different methods should therefore not be assumed to be interchangeable. A calculated LDL result is not a diagnosis and should be interpreted as part of the full lipid profile and clinical history. Non-HDL cholesterol includes cholesterol carried by all potentially atherogenic particles and can remain useful when triglycerides are elevated, although its treatment thresholds are also context dependent. Do not start, stop, or change statin or other lipid medication based only on this page. Discuss unexpectedly high, very low, or changing values with a qualified professional. Healthy dietary patterns, physical activity, tobacco avoidance, blood pressure management, and diabetes care complement medication when indicated. Extremely high cholesterol can suggest an inherited disorder and warrants timely medical assessment and, in some cases, family screening.