Cholesterol Calculator

Health Diet and Nutrition Planning

Most lab reports estimate LDL with the Friedewald equation: LDL = total cholesterol − HDL − triglycerides ÷ 5, all in mg/dL (divide triglycerides by 2.2 in mmol/L). A panel of 200 total, 50 HDL and 150 triglycerides gives an LDL of 120 mg/dL, which ATP III calls near optimal.

About this tool

A standard lipid panel measures total cholesterol, HDL and triglycerides directly and usually calculates LDL from them. This calculator repeats that arithmetic so you can check a report, convert a panel between mg/dL and mmol/L thinking, or see what a changed number does to LDL. It returns the estimated LDL, its NCEP ATP III band, non-HDL cholesterol, the VLDL estimate and the total-to-HDL ratio, with each line of working shown. The Friedewald method assumes a fixed ratio of triglycerides to VLDL cholesterol, so it is refused at triglycerides of 400 mg/dL or more, and it reads less reliably in non-fasting samples or at very low LDL. It does not estimate heart risk, which also depends on age, blood pressure, smoking and diabetes.

How to use it

Pick the lab units
Choose mg/dL, used in the US, or mmol/L, used in the UK, Canada, Australia and most of Europe.
Copy three numbers from the report
Enter total cholesterol, HDL and triglycerides exactly as printed.
Read LDL and the extras
The LDL estimate, its band, non-HDL and the ratio update as you type, with the working below.

Examples

TC 200, HDL 50, TG 150 mg/dL

Lab units: mg/dL (US)
Total cholesterol: 200
HDL cholesterol: 50
Triglycerides: 150

Result Estimated LDL cholesterol: 120
ATP III LDL category: Near optimal
Non-HDL cholesterol: 150 mg/dL
Estimated VLDL: 30 mg/dL
Total : HDL ratio: 4

VLDL = triglycerides ÷ 5 = 150 ÷ 5 = 30 mg/dL
LDL = 200 − 50 − 30 = 120 mg/dL
Non-HDL = 200 − 50 = 150 mg/dL
Total ÷ HDL = 200 ÷ 50 = 4

Triglycerides of 150 mg/dL stand for about 30 mg/dL of VLDL, which leaves an LDL of 120 mg/dL, in the ATP III near-optimal band.

TC 5.0, HDL 1.3, TG 1.1 mmol/L

Lab units: mmol/L
Total cholesterol: 5
HDL cholesterol: 1.3
Triglycerides: 1.1

Result Estimated LDL cholesterol: 3.2
ATP III LDL category: Near optimal
Non-HDL cholesterol: 3.7 mmol/L
Estimated VLDL: 0.5 mmol/L
Total : HDL ratio: 3.8

VLDL = triglycerides ÷ 2.2 = 1.1 ÷ 2.2 = 0.5 mmol/L
LDL = 5 − 1.3 − 0.5 = 3.2 mmol/L
Non-HDL = 5 − 1.3 = 3.7 mmol/L
Total ÷ HDL = 5 ÷ 1.3 = 3.8

In mmol/L the triglyceride divisor is 2.2, so VLDL is 0.5 and LDL is 3.2 mmol/L, about 124 mg/dL.

TC 260, HDL 40, TG 200 mg/dL

Lab units: mg/dL (US)
Total cholesterol: 260
HDL cholesterol: 40
Triglycerides: 200

Result Estimated LDL cholesterol: 180
ATP III LDL category: High
Non-HDL cholesterol: 220 mg/dL
Estimated VLDL: 40 mg/dL
Total : HDL ratio: 6.5

VLDL = triglycerides ÷ 5 = 200 ÷ 5 = 40 mg/dL
LDL = 260 − 40 − 40 = 180 mg/dL
Non-HDL = 260 − 40 = 220 mg/dL
Total ÷ HDL = 260 ÷ 40 = 6.5

260 − 40 − 40 gives an LDL of 180 mg/dL, in the 160–189 high band, with a total-to-HDL ratio of 6.5.

How it is calculated

LDL = TC − HDL − TG ÷ 5 (mg/dL); LDL = TC − HDL − TG ÷ 2.2 (mmol/L)

TC: total cholesterol
HDL: high-density lipoprotein cholesterol
TG: triglycerides; TG ÷ 5 or TG ÷ 2.2 estimates VLDL cholesterol

Total cholesterol is carried by LDL, HDL and VLDL particles. Friedewald, Levy and Fredrickson (1972) estimated VLDL cholesterol as one fifth of triglycerides in mg/dL, so subtracting HDL and that estimate from the total leaves LDL. The category uses the ATP III bands: under 100 optimal, 100–129 near optimal, 130–159 borderline high, 160–189 high, 190 or more very high, with mmol/L results converted at 38.67 mg/dL per mmol/L. Non-HDL is total minus HDL.

Sources

ATP III Guidelines At-A-Glance Quick Desk Reference — National Heart, Lung, and Blood Institute
Cholesterol Levels — MedlinePlus, U.S. National Library of Medicine

When not to use it

With triglycerides at 400 mg/dL (4.5 mmol/L) or above, where only a directly measured LDL is meaningful.
To judge treatment targets or heart risk, which depend on factors this calculation does not see.
For children, whose cholesterol bands differ from the adult ATP III cut-offs.

Common mistakes

Mixing units, such as total cholesterol in mmol/L and triglycerides in mg/dL.
Using a non-fasting triglyceride value and treating the LDL estimate as exact.
Dividing mmol/L triglycerides by 5 instead of 2.2.

Frequently asked questions

Why is my lab's LDL slightly different from this result?

Many labs now use the Martin-Hopkins or Sampson equation, or measure LDL directly, especially when triglycerides are high or LDL is low. Those methods can differ from Friedewald by several mg/dL. Check the report's footnote for the method used.

What is non-HDL cholesterol?

Non-HDL cholesterol is total cholesterol minus HDL. It counts the cholesterol in every particle that can build up in artery walls, including VLDL and remnants, and it does not depend on fasting. ATP III sets its goals 30 mg/dL above the matching LDL goal.

How do I convert cholesterol between mg/dL and mmol/L?

For total, HDL and LDL cholesterol, multiply mmol/L by 38.67 to get mg/dL. Triglycerides use a different factor, 88.57, because the molecule is heavier. So 5.0 mmol/L of cholesterol is about 193 mg/dL.

What does the total-to-HDL ratio show?

It divides total cholesterol by HDL. A lower ratio means a larger share of cholesterol is carried by HDL. Ratios are used in some risk scores, such as QRISK in the UK, but they are not a diagnosis on their own.

Why does the calculator refuse very high triglycerides?

At triglycerides of 400 mg/dL or more, the one-fifth rule for VLDL breaks down and Friedewald underestimates or overestimates LDL badly. The original 1972 paper excluded these samples, and labs switch to a direct LDL test.

What HDL level counts as low?

ATP III lists HDL below 40 mg/dL (about 1.0 mmol/L) as low and 60 mg/dL or more as high. The calculator adds a note when HDL falls below 40 mg/dL.

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APA

Tools Directory Editorial Team. (2026, October 28). Cholesterol Calculator. Tools Directory. Retrieved October 28, 2026, from https://tools.milunir.com/health/diet-and-nutrition-planning/cholesterol-calculator/

MLA

Tools Directory Editorial Team. “Cholesterol Calculator.” Tools Directory, 28 Oct. 2026, https://tools.milunir.com/health/diet-and-nutrition-planning/cholesterol-calculator/. Accessed 28 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Cholesterol Calculator.” Tools Directory. Last modified October 28, 2026. Accessed October 28, 2026. https://tools.milunir.com/health/diet-and-nutrition-planning/cholesterol-calculator/.

Link

<a href="https://tools.milunir.com/health/diet-and-nutrition-planning/cholesterol-calculator/">Cholesterol Calculator – Tools Directory</a>