LDL Cholesterol (Friedewald) Calculator
The Friedewald equation estimates LDL ("bad") cholesterol from the rest of a standard lipid panel: LDL equals total cholesterol minus HDL minus triglycerides divided by 5, all in mg/dL. It has been the standard calculated LDL value since 1972. The estimate is reliable only when triglycerides are below 400 mg/dL, so this calculator flags results above that level. Enter your total cholesterol, HDL and triglycerides to estimate LDL. This tool is for education and is not a substitute for medical advice.
Friedewald formula (mg/dL)
VLDL = triglycerides / 5 LDL = total cholesterol - HDL - VLDL Valid only when triglycerides are below 400 mg/dL
For mmol/L units, divide triglycerides by 2.2 instead of 5.
Worked example
Total cholesterol 200, HDL 50, triglycerides 150. VLDL = 150 / 5 = 30. LDL = 200 - 50 - 30 = 120.00 mg/dL, which is near optimal.
LDL Friedewald: frequently asked questions
What is the Friedewald equation?
The Friedewald equation estimates low-density lipoprotein (LDL) cholesterol from a standard lipid panel: LDL equals total cholesterol minus HDL cholesterol minus triglycerides divided by 5 (all in mg/dL). The triglycerides-over-5 term estimates very-low-density lipoprotein (VLDL) cholesterol. It has been the standard calculated LDL since 1972.
When is the Friedewald estimate not valid?
The equation becomes unreliable when triglycerides are 400 mg/dL or higher, because the triglycerides-over-5 estimate of VLDL no longer holds. It is also less accurate at very low LDL levels. In those cases a directly measured LDL or a different formula should be used. This calculator flags results where triglycerides are 400 or above.
What units does this use?
This calculator uses conventional US units of milligrams per decilitre (mg/dL). If your lab reports in millimoles per litre (mmol/L), as is common outside the US, the divisor for the triglycerides term is 2.2 rather than 5. Convert your values to mg/dL first, or use a calculator set up for mmol/L.
What LDL level is considered healthy?
US guidelines generally describe an LDL below 100 mg/dL as optimal, 100 to 129 as near optimal, 130 to 159 as borderline high, 160 to 189 as high, and 190 or above as very high. Your personal target depends on your overall cardiovascular risk; discuss it with your clinician. This tool is for education, not diagnosis.
Official sources
- National Heart, Lung, and Blood Institute: Blood Cholesterol.
- MedlinePlus (National Library of Medicine): LDL: The Bad Cholesterol.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.