Cholesterol LDL/HDL Calculator
A lipid panel (cholesterol blood test) measures total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol, and triglycerides. These values together help assess your cardiovascular disease risk. This calculator takes your lipid panel results, classifies each value according to AHA and NHLBI guidelines, and computes derived values including non-HDL cholesterol, total cholesterol to HDL ratio, and LDL estimate via the Friedewald equation (if LDL is not directly measured). Understanding your lipid profile is a key step in managing your long-term cardiovascular health. All values should be in mg/dL, the standard unit used by US laboratory reports.
Cholesterol formulas (AHA guidelines)
LDL (Friedewald) = Total Chol - HDL - (Triglycerides / 5)
Non-HDL = Total Cholesterol - HDL
Cardiac risk ratio = Total Cholesterol / HDL
Valid when triglycerides are below 400 mg/dL
Cholesterol: frequently asked questions
What are normal cholesterol levels?
Per the American Heart Association: Total cholesterol below 200 mg/dL is desirable; 200-239 borderline high; 240+ high. LDL below 100 mg/dL is optimal; 100-129 near-optimal; 130-159 borderline high; 160+ high. HDL of 60 mg/dL or higher is protective; below 40 in men and 50 in women is low (risk factor).
What is LDL (bad) cholesterol?
Low-density lipoprotein (LDL) is the primary carrier of cholesterol in the blood. High LDL levels cause cholesterol to build up in artery walls (atherosclerosis), increasing risk of heart attack and stroke. LDL targets vary by individual cardiovascular risk; people with diabetes or prior heart disease often aim for below 70 mg/dL.
What is HDL (good) cholesterol?
High-density lipoprotein (HDL) removes excess cholesterol from the bloodstream and returns it to the liver for removal. High HDL is associated with reduced cardiovascular risk. Exercise is the most effective lifestyle intervention for raising HDL. Low HDL (below 40 mg/dL for men) is an independent cardiovascular risk factor.
What is the total cholesterol to HDL ratio?
The total cholesterol to HDL ratio (also called the cardiac risk ratio) is calculated by dividing total cholesterol by HDL. A ratio below 4.0 is desirable; below 3.5 is optimal. A high ratio (above 5.0) indicates elevated cardiovascular risk. The AHA considers this ratio a useful risk assessment tool.
How is LDL calculated without a direct measurement?
The Friedewald equation estimates LDL: LDL = Total Cholesterol - HDL - (Triglycerides / 5). This formula is used when total cholesterol, HDL, and triglycerides are measured directly but LDL is not. It is accurate when triglycerides are below 400 mg/dL; above that level, direct LDL measurement is needed.
Official sources
- American Heart Association: About Cholesterol.
- National Heart, Lung, and Blood Institute: Blood Cholesterol.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.