VLDL Cholesterol Calculator
VLDL Cholesterol Calculator
Estimate VLDL cholesterol as a fifth of the triglyceride concentration — the same assumption Friedewald rests on, with the same limits.
VLDL Cholesterol
TG ÷ 5 → mg/dLTriglycerides 140 mg/dL (fasting)
Formula
VLDL-C = triglycerides ÷ 2.2 (mmol/L)
- ÷ 5
- assumes a fixed VLDL cholesterol to triglyceride ratio of 1:5 in a fasting sample — the same assumption the Friedewald equation makes
- ÷ 2.2
- the equivalent divisor when both terms are in mmol/L, because cholesterol and triglyceride have different molar conversion factors
- reference method
- true VLDL cholesterol is measured by ultracentrifugation and beta-quantification, not by any equation
Worked example
Triglycerides 140 mg/dL (fasting)
140 ÷ 5 = 28 mg/dL
Below 30 → within the usual range
The same 28 mg/dL is what a Friedewald LDL on this sample would subtract
Estimated VLDL against the triglyceride it comes from
| Triglycerides (mg/dL) | Estimated VLDL-C (mg/dL) | Category |
|---|---|---|
| < 150 | < 30 | Normal |
| 150 – 199 | 30 – 39 | Borderline high |
| 200 – 399 | 40 – 79 | High |
| ≥ 400 | Not valid | Estimate should not be used |
An estimate, not a measurement
This figure is an estimate and should be read as one. True VLDL cholesterol is measured by ultracentrifugation followed by beta-quantification, the reference method that separates lipoproteins by density and assays the cholesterol in each fraction. That is a specialist procedure performed in reference laboratories, so routine practice substitutes an arithmetic estimate: one fifth of the triglyceride concentration in mg/dL.
The divisor of 5 is the same assumption the Friedewald equation rests on — a fixed ratio of VLDL cholesterol to triglyceride in a fasting sample. Anything that breaks the assumption breaks both calculations at once. Above a triglyceride of 400 mg/dL the ratio no longer holds and the estimate should not be used. In type III dysbetalipoproteinaemia, cholesterol-rich remnants carry far more cholesterol per unit of triglyceride than the divisor allows, and the estimate is substantially too low. In a non-fasting sample, chylomicron triglyceride is counted as though it were VLDL and the estimate reads too high.
Because the result is a fixed fraction of a number already on the report, it adds no information the triglyceride did not already carry. Its real use is explanatory: it shows how much of a total cholesterol is being attributed to VLDL when an LDL is calculated, which makes the Friedewald subtraction visible rather than hidden. A patient with a triglyceride of 350 mg/dL has 70 mg/dL of the total cholesterol assigned to VLDL by assumption alone.
Where the cholesterol carried in triglyceride-rich particles genuinely matters — residual risk in treated patients, or a suspected remnant disorder — remnant cholesterol calculated as non-HDL cholesterol minus LDL cholesterol, or a directly measured LDL alongside non-HDL, is more informative than this estimate. Non-HDL cholesterol is the practical alternative in day-to-day work, because it captures VLDL and remnant cholesterol without assuming anything about the ratio between them.
Frequently asked questions
How is VLDL cholesterol calculated?
By dividing the fasting triglyceride concentration by five when both are in mg/dL, or by 2.2 when both are in mmol/L. It is an estimate rather than a measurement.
What is a normal VLDL cholesterol?
Below about 30 mg/dL, which corresponds to a triglyceride below 150 mg/dL. Values of 30 to 40 mg/dL are borderline high and above 40 mg/dL are high.
Why can VLDL not be estimated when triglycerides are very high?
The fixed one-to-five ratio between VLDL cholesterol and triglyceride only holds at ordinary fasting concentrations. Above 400 mg/dL the composition of the particles changes and the estimate is no longer reliable.
How is VLDL cholesterol actually measured?
By ultracentrifugation and beta-quantification, which physically separate lipoproteins by density before assaying the cholesterol in each fraction. This is a reference laboratory method, not a routine test.
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References
- Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem. 1972;18(6):499–502.
- Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Third Report of the National Cholesterol Education Program (NCEP) Expert Panel (Adult Treatment Panel III) final report. Circulation. 2002;106(25):3143–3421.