Lipid Panel Calculator & Workspace

Total cholesterol plus HDL-C produces non-HDL-C and the TC/HDL ratio. Adding triglycerides can also produce traditional Friedewald LDL-C, its estimated VLDL-C audit term and LDL/HDL. If a reported LDL-C is entered instead, the page retains it as Entered / Reported and derives LDL/HDL without claiming that LDL-C was Friedewald-calculated.

Sources: [1, 6]

LDL-C = total cholesterol − HDL-C − (triglycerides ÷ 5), with all three submitted measurements in mg/dL. The triglyceride-divisor term is a traditional estimate of VLDL-C, not a measured VLDL-C value.

Sources: [1]

LDL-C = total cholesterol − HDL-C − (triglycerides ÷ 2.2), with all three submitted measurements in mmol/L. The page does not convert a mixed-unit panel or use the mg/dL divisor in SI units.

Sources: [1]

The original method used a fixed triglyceride-to-VLDL-cholesterol relationship: 5 when concentrations are expressed in mg/dL and 2.2 in mmol/L. That relationship varies between samples and people, which is an important limitation of the estimate.

Sources: [1]

The reported-LDL mode labels the entered value Entered / Reported and does not run an LDL-C estimation equation. The triglyceride mode labels its LDL-C Calculated and identifies the traditional Friedewald method. A homogeneous direct assay, another equation and beta-quantification remain different procedures and are not inferred from the number alone.

Sources: [1, 6]

This page uses a strict half-open boundary: 399.9 mg/dL and 4.49 mmol/L can be submitted, while 400 mg/dL and 4.5 mmol/L are withheld. At and above the boundary, use the LDL-C method selected and reported by the laboratory or clinical workflow.

Sources: [1, 6]

No. It only permits the historical arithmetic. The fixed TG:VLDL-C assumption can still disagree with a reference method, particularly when triglycerides are higher or LDL-C is lower. Sampling and assay variation also remain.

Sources: [1, 2, 5]

Not in the current U.S. guideline. The 2026 ACC/AHA multisociety dyslipidemia guideline prefers Martin/Hopkins or Sampson/NIH over Friedewald for estimation from a standard lipid profile. This page intentionally stays with the 1972 model and never switches methods silently.

Sources: [3, 4, 10, 11]

No. All values used in one record must come from the same specimen and clinical time point and use the selected unit. Combining different dates, laboratories, treatment states, or units can produce arithmetic that describes neither record. Changing the unit clears every numeric field so an old number cannot be reinterpreted silently.

Sources: [1, 6, 9]

The original 1972 Friedewald relationship was derived from fasting plasma data and depends on a fixed triglyceride-to-VLDL-C ratio. Modern guidance allows fasting or nonfasting standard lipid profiles for many people and prefers Martin/Hopkins or Sampson/NIH for estimated LDL-C. The fixed historical assumption may not hold with triglyceride metabolism abnormalities, chylomicrons, type III dysbetalipoproteinemia, or clearly high triglycerides. This page cannot identify whether a sample was truly fasting, contains chylomicrons, has type III dysbetalipoproteinemia or unusual VLDL composition, or which LDL-C method the laboratory used. Being below 400 mg/dL or 4.5 mmol/L only permits this historical arithmetic; it does not prove that the estimate is accurate or applicable to the sample.

Sources: [1, 6, 9]

Non-HDL-C is total cholesterol minus HDL-C and is available from every supported record mode because all three require TC and HDL-C. It includes cholesterol in multiple non-HDL lipoprotein classes and is not the same value as LDL-C. Total cholesterol equal to HDL-C produces a valid arithmetic zero; HDL-C above total cholesterol is rejected rather than converted into a negative concentration.

Sources: [6, 8]

No. LDL-C estimates cholesterol mass carried within LDL particles. It does not count particles. Apolipoprotein B and other particle-related tests answer different questions and are not derived by this calculator.

Sources: [6, 8]

They are unitless arithmetic quotients because the same concentration unit cancels during division. TC/HDL is available when TC and positive HDL-C are entered. LDL/HDL is available only when LDL-C is either explicitly reported or successfully calculated by the selected Friedewald mode. Different absolute lipid values can produce the same ratio, so the quotient does not replace the source concentrations. Neither ratio is turned into a universal risk category or treatment target.

Sources: [6, 10]

For some combinations, the fixed triglyceride-divisor term is as large as or larger than non-HDL-C. The page does not clamp that arithmetic to zero or present it as a usable LDL-C estimate; it withholds the result and asks for verification.

Sources: [1, 6]

The laboratory may use Martin/Hopkins, Sampson/NIH, a homogeneous direct assay or another stated method, and rounding or assay calibration can also differ. Use the reported-LDL mode when retaining that laboratory value; do not treat unlike methods as interchangeable trends.

Sources: [2, 3, 4, 5, 6]

No. The workspace supplies source-labeled lipid arithmetic only. It does not diagnose a lipid disorder, calculate ASCVD risk, establish a patient-specific goal, select a medicine, prescribe a dose or recommend treatment.

Sources: [10, 11]