LDL Cholesterol Calculator
Estimate your LDL cholesterol with the Sampson/NIH 2020 equation : the current preferred method : with the classic Friedewald estimate shown alongside for comparison.
Enter Your Values
Typical range: 50-800 mg/dL or 1.3-20.7 mmol/L : validated against your selected unit.
Typical range: 10-150 mg/dL or 0.26-3.9 mmol/L.
Typical range: 10-2000 mg/dL or 0.11-22.6 mmol/L.
Enter your values and press Calculate: you will get the result, its method, the inputs used and confidence, plus copy, print and share options.
How this calculator works
Sampson/NIH LDL-C (2020)v1.0.0
LDL-C = TC/0.948 − HDL/0.971 − (TG/8.56 + TG×nonHDL/2140 − TG²/16100) − 9.44. Valid up to TG 800 mg/dL.
- Applies to
- Adults with fasting or non-fasting panels
- Assumptions
- Standard lipid panel assays
- Limitations
- Still an estimate vs direct LDL-C measurement; Not a cardiovascular diagnosis
- Output
- mg/dL
- Last reviewed
- 2026-06-01
Friedewald LDL-C (legacy)v1.0.0
LDL = TC − HDL − TG/5. Shown only as a legacy comparison; invalid above TG 400 mg/dL.
- Applies to
- Historical comparison only
- Assumptions
- Fasting sample; TG ≤ 400 mg/dL
- Limitations
- Underestimates LDL at high TG and low LDL
- Output
- mg/dL
- Last reviewed
- 2026-06-01
Evidence Sources & Literature
- JAMA Cardiology (NIH). A New Equation for Calculation of Low-Density Lipoprotein Cholesterol in Patients With Normolipidemia and/or Hypertriglyceridemia. JAMA Cardiol, 2020. doi:10.1001/jamacardio.2020.0010.
- Clinical Chemistry. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem, 1972. doi:10.1093/clinchem/18.6.499.
About the LDL Cholesterol Calculator
LDL cholesterol is the number most people have heard described as the bad cholesterol, because higher levels are linked with a greater risk of heart disease over time. This calculator estimates your LDL from the other values on a standard lipid panel (your total cholesterol, HDL and triglycerides) using the Sampson/NIH 2020 equation, the current preferred method, and shows the long-established Friedewald estimate alongside it for comparison, so you can understand a result even if your lab did not report LDL directly.
As with any cholesterol tool, I want to set expectations: this is for education, not diagnosis. LDL is important, but it is one factor among several your doctor weighs. Use this to understand your numbers, then discuss them with a professional who knows your full history.
What LDL is and why it matters
LDL (low-density lipoprotein) carries cholesterol through your bloodstream, and when there is too much of it, cholesterol can build up in artery walls over the years, narrowing them. That is why keeping LDL in a healthy range is a cornerstone of heart-disease prevention. It is not that LDL is evil, your body needs cholesterol, it is that persistently high levels raise long-term risk.
How the estimate is calculated
The calculator uses the Sampson/NIH 2020 equation as its primary method. It estimates LDL from total cholesterol, HDL and triglycerides using a more elaborate formula that stays reliable at triglyceride levels where the older Friedewald equation breaks down, and it is valid up to triglycerides of 800 mg/dL. The classic Friedewald estimate (total cholesterol minus HDL minus one-fifth of triglycerides) is shown alongside it as a legacy comparison, because many labs used it for decades. When the two disagree noticeably, the Sampson/NIH figure is the more trustworthy one.
How to read your LDL
As a general guide, an LDL under about 100 mg/dL is considered optimal for many adults, with higher numbers prompting closer attention. But targets are personal: someone with existing heart disease or diabetes is usually advised to aim lower than someone at low overall risk. This is exactly why I keep pointing back to your doctor, the right LDL target for you depends on your whole risk profile, not a single chart.
Lowering LDL through habits
Diet and lifestyle genuinely move LDL. Eating more soluble fiber (oats, beans, barley, apples), replacing saturated and trans fats with unsaturated fats from olive oil, nuts and fish, staying active, not smoking and reaching a healthy weight all help. For some people these changes are enough; for others, particularly those at higher risk, a doctor may add medication. The calculator helps you track where you stand as you work on those habits.
Dietitian Insight: The Sampson-NIH equation provides enhanced precision for estimating LDL cholesterol across wide triglyceride ranges. Discover clinical lifestyle interventions for lipid management, or evaluate vascular risk ratios with our cholesterol ratio calculator.
Sources & method
This calculator uses established, peer-reviewed formulas and reference ranges from recognized health and nutrition authorities. Results are estimates for general education, not a medical diagnosis. For decisions about your health, consult a qualified clinician. Reviewed by Macro & Meals Editorial Team, Content editor.
Frequently Asked Questions
How is LDL cholesterol calculated?
This tool uses the Sampson/NIH 2020 equation as its primary method : the current preferred approach, valid up to triglycerides of 800 mg/dL : and shows the classic Friedewald estimate (LDL = total cholesterol − HDL − triglycerides/5) alongside it for comparison.
What is a healthy LDL level?
As a general guide, an LDL under about 100 mg/dL is considered optimal for many adults. But the right target is personal: people with existing heart disease or diabetes are usually advised to aim lower. Your doctor sets the appropriate target based on your overall risk.
Why is LDL called bad cholesterol?
Because when LDL is too high, cholesterol can build up in artery walls over time and narrow them, raising the risk of heart disease. Your body does need some cholesterol, so LDL is not inherently harmful; it is persistently high levels that increase long-term risk.
How can I lower my LDL?
Eating more soluble fiber from oats, beans and fruit, swapping saturated and trans fats for unsaturated fats from olive oil, nuts and fish, staying active, not smoking and reaching a healthy weight all help. For some people lifestyle is enough; others at higher risk may need medication a doctor prescribes.
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