Estimate LDL cholesterol with the Sampson/NIH or Friedewald equation, and calculate non-HDL from total cholesterol and HDL. Select the units on your reportand read the limits before using the result.
JavaScript is required for calculation. The usage guide and sources are available below.
How to use this calculator
- Use values from the same blood sample. Select mg/dL or mmol/L for each item.
- If triglycerides are missing, choose “Non-HDL only”. Otherwise choose an LDL equation and record fasting status.
- Click Calculate and read the explanation. Preview the summary, then choose Print / Save PDF to keep a copy.
Worked example
For total cholesterol 200, HDL 50 and triglycerides 150 mg/dL, non-HDL is 150 mg/dL. Sampson estimates LDL at about 123.4 mg/dL; Friedewald gives 120.0 mg/dL when fasting is confirmed. These are demonstration values, not treatment goals. “Fill example” populates them; initial fields are empty.
Why might the laboratory LDL differ?
Different laboratories use different equations or direct assays. This calculator defaults to the public-domain Sampson/NIH equation. A result is an estimate, not a replacement for the laboratory value. Comparisons over time should use the same method and similar test conditions.
When LDL is not estimated
This tool withholds Sampson LDL at triglycerides ≥800 mg/dL, and Friedewald LDL at ≥400 mg/dL or when fasting is not confirmed. A zero/negative LDL or an LDL estimate greater than non-HDL is also withheld. Non-HDL remains available when total cholesterol and HDL inputs are valid. High triglycerides need clinical attention independently of the LDL estimate.
Equations and units
Non-HDL = total cholesterol − HDL. Friedewald LDL = total cholesterol − HDL − triglycerides/5, with all values in mg/dL.
Sampson LDL = TC/0.948 − HDL/0.971 − (TG/8.56 + TG × non-HDL/2140 − TG²/16100) − 9.44, in mg/dL. The tool converts mmol/L inputs internally: cholesterol mg/dL ×0.02586 = mmol/L; triglyceride mg/dL ×0.01129 = mmol/L. Original inputs and units remain in the summary.
Fasting, risk and personal targets
Many initial lipid assessments can use non-fasting samples, but high triglycerides or a provider’s instructions may require a fasting repeat. The numeric adult bands shown here are not personal LDL/non-HDL goals. Current US and Korean guidance consider overall risk, previous cardiovascular disease and other clinical factors. This tool does not calculate a cardiovascular-risk score or decide whether medication is needed.
Frequently asked questions
Can I calculate non-HDL without triglycerides?
Yes. Only total cholesterol and HDL are needed; use the non-HDL-only option.
Does a low LDL estimate mean I am low risk?
No. Risk depends on several factors, and a calculation can be inaccurate. Review your laboratory report and your overall risk with a clinician.
How do I download the PDF?
Open the result preview, click Print / Save PDF, and choose “Save as PDF” in the browser. You can include a blank lipid-results log.
Related guide, log and calculators
Lipid panel guide · Blood pressure and lab results log · Lab result guide · Health records · Blood pressure calculator · HbA1c/eAG calculator
Sources
- Sampson et al. (2020): original LDL equation
- CDC NHANES: LDL equations and unit conversion
- Korean Society of Lipid and Atherosclerosis
- KSoLA fifth-edition dyslipidemia guideline (2022)
- ADLM (2024): measurement and reporting of lipids
- ACC/AHA 2026 dyslipidemia guideline update
- MedlinePlus: pancreatitis and high triglycerides
Sources checked 2026-09-30 · General information, not a substitute for care. No independent clinician review is claimed.