LDL Cholesterol & Lipid Panel Calculator

Total cholesterol plus HDL-C produces non-HDL-C and the TC/HDL ratio. Adding triglycerides produces a primary Sampson/NIH LDL-C estimate and LDL/HDL, with traditional Friedewald shown only as a historical comparison when available. If a reported LDL-C is entered instead, the page retains it as Entered / Reported and derives LDL/HDL without inferring how the laboratory obtained that LDL-C.

Sources: [1, 4, 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]

After normalizing the panel to mg/dL, the page uses LDL-C = TC ÷ 0.948 − HDL-C ÷ 0.971 − (TG ÷ 8.56 + TG × non-HDL-C ÷ 2140 − TG² ÷ 16100) − 9.44. This is the published Sampson/NIH 2020 equation, not Martin/Hopkins, Friedewald, a direct assay, or beta-quantification.

Sources: [4]

The reported-LDL mode labels the entered value Entered / Reported and does not run an LDL-C estimation equation. The triglyceride mode identifies Sampson/NIH as its primary calculation and Friedewald as a historical comparison. A homogeneous direct assay, another equation and beta-quantification remain different procedures and are not inferred from the number alone.

Sources: [1, 4, 6]

This page uses a conservative half-open boundary: 399.9 mg/dL and 4.49 mmol/L can be submitted, while both Sampson/NIH and Friedewald LDL-C are withheld at 400 mg/dL or 4.5 mmol/L and above. Non-HDL-C and TC/HDL remain available. A 2026 beta-quantification study found poor performance for every tested LDL-C equation in the 401–800 mg/dL triglyceride range.

Sources: [6, 12]

No. It only permits the selected arithmetic. Every LDL-C equation is an estimate and can disagree with beta-quantification, direct assays, or another equation. Higher triglycerides, lower LDL-C, unusual lipoprotein composition, sampling, and assay variation can all matter.

Sources: [4, 5, 12]

No. The 2026 ACC/AHA multisociety dyslipidemia guideline prefers Martin/Hopkins or Sampson/NIH over Friedewald for estimation from a standard lipid profile. This page uses Sampson/NIH as the primary calculated estimate, retains Friedewald only as a labeled historical comparison, and does not run Martin/Hopkins.

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, while modern guidance allows fasting or nonfasting standard lipid profiles for many people. Sampling context still affects triglycerides, and this page cannot verify fasting status, chylomicrons, type III dysbetalipoproteinemia, unusual lipoprotein composition, or the method used by a laboratory. Being below 400 mg/dL or 4.5 mmol/L permits this page's estimates; it does not prove accuracy or applicability to a particular sample.

Sources: [1, 6, 9, 12]

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 explicitly reported or the primary Sampson/NIH estimate is available. 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]

Some source-value combinations can produce a nonpositive calculated LDL-C. The page does not clamp Sampson/NIH or Friedewald arithmetic to zero or present it as a usable LDL-C estimate; it withholds that estimate while retaining other measures the record can support.

Sources: [1, 4, 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]