acalculator

What is my LDL cholesterol?

Enter total cholesterol, HDL cholesterol, and triglycerides from a lipid panel to estimate LDL cholesterol and see its ATP III category. For information only. This is not medical advice or a diagnosis. Do not use it to make treatment decisions without a clinician. No licensed clinician has reviewed this page.

Your numbers

Units
Equation
LDL cholesterol (mg/dL)
120

The estimated LDL cholesterol is 120 mg/dL (3.1 mmol/L): Near or above optimal (100 to 129 mg/dL).

Near or above optimal (100 to 129 mg/dL)

  1. Optimal (under 100 mg/dL)
  2. Near or above optimal (100 to 129 mg/dL)
  3. Borderline high (130 to 159 mg/dL)
  4. High (160 to 189 mg/dL)
  5. Very high (190 mg/dL or more)
LDL cholesterol (mmol/L)
3.1
ATP III category
Near or above optimal (100 to 129 mg/dL)
Non-HDL cholesterol (mg/dL)
150
Non-HDL cholesterol (mmol/L)
3.88

LDL cholesterol (mg/dL): 120. The estimated LDL cholesterol is 120 mg/dL (3.1 mmol/L): Near or above optimal (100 to 129 mg/dL).

Where does the LDL sit?

This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use

How to calculate

Estimates LDL cholesterol from total cholesterol, HDL cholesterol, and triglycerides with the Friedewald or the Sampson (NIH) equation, in mg/dL or mmol/L, and shows its NCEP ATP III category.

Example with the default inputs (Units mg/dL, Equation Friedewald, Total cholesterol (mg/dL) 200, HDL cholesterol (mg/dL) 50, Triglycerides (mg/dL) 150): The estimated LDL cholesterol is 120 mg/dL (3.1 mmol/L): Near or above optimal (100 to 129 mg/dL).

Method: Friedewald: LDL = TC − HDL − TG ÷ 5 (mg/dL, TG under 400). Sampson NIH equation 2: LDL = TC/0.948 − HDL/0.971 − (TG/8.56 + TG × non-HDL/2140 − TG²/16100) − 9.44 (mg/dL, TG up to 800). SI values convert with 0.02586 (cholesterol) and 0.0113 (triglycerides) mmol/L per mg/dL.

  • Total cholesterol, HDL cholesterol, and triglycerides come from the same blood sample.
  • The LDL estimate is worked from the exact typed values and rounded once: to a whole mg/dL, and to 2 decimals in mmol/L.
  • The ATP III category is read from the whole mg/dL value shown.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Units mg/dL, Equation Friedewald, Total cholesterol (mg/dL) 200, HDL cholesterol (mg/dL) 50, Triglycerides (mg/dL) 150 gives LDL cholesterol (mg/dL) 120, LDL cholesterol (mmol/L) 3.1, ATP III category Near or above optimal (100 to 129 mg/dL), Non-HDL cholesterol (mg/dL) 150, Non-HDL cholesterol (mmol/L) 3.88.Source: Friedewald 1972: 200 − 50 − 150 ÷ 5 = 120 mg/dL
  2. Units mg/dL, Equation Sampson (NIH), Total cholesterol (mg/dL) 200, HDL cholesterol (mg/dL) 50, Triglycerides (mg/dL) 150 gives LDL cholesterol (mg/dL) 123, LDL cholesterol (mmol/L) 3.19, ATP III category Near or above optimal (100 to 129 mg/dL).Source: Sampson 2020 NIH equation 2: 210.970 − 51.493 − (17.523 + 10.514 − 1.398) − 9.44 = 123.397 mg/dL
  3. Units mg/dL, Equation Sampson (NIH), Total cholesterol (mg/dL) 260, HDL cholesterol (mg/dL) 35, Triglycerides (mg/dL) 500 gives LDL cholesterol (mg/dL) 133, LDL cholesterol (mmol/L) 3.45, ATP III category Borderline high (130 to 159 mg/dL), Non-HDL cholesterol (mg/dL) 225.Source: Sampson 2020 NIH equation 2 = 133.323 mg/dL
  4. Units mg/dL, Equation Friedewald, Total cholesterol (mg/dL) 240, HDL cholesterol (mg/dL) 40, Triglycerides (mg/dL) 300 gives LDL cholesterol (mg/dL) 140, LDL cholesterol (mmol/L) 3.62, ATP III category Borderline high (130 to 159 mg/dL), Non-HDL cholesterol (mg/dL) 200.Source: Friedewald 1972: 240 − 40 − 60 = 140 mg/dL
  5. Units mmol/L, Equation Friedewald, Total cholesterol (mmol/L) 5.2, HDL cholesterol (mmol/L) 1.3, Triglycerides (mmol/L) 1.7 gives LDL cholesterol (mg/dL) 121, LDL cholesterol (mmol/L) 3.12, Non-HDL cholesterol (mmol/L) 3.9.

Medical disclaimer

This calculator is for information and education only. It is not medical advice, and its result is not a diagnosis. Do not use it to start, stop, or change a treatment without a clinician who knows your health history. No licensed clinician has reviewed this page. This site's editors checked the formulas and worked examples against published sources. If you think you have a medical emergency, call your local emergency number.

When this does not apply. Both equations estimate LDL in adults from a standard lipid panel. Friedewald does not apply when triglycerides are 400 mg/dL or more; the Sampson equation was checked up to 800 mg/dL. Neither applies to people with type III hyperlipoproteinemia (dysbetalipoproteinemia); Sampson et al. left those samples out. The page refuses these triglyceride ranges with a message.

How it works

All three inputs are in mg/dL (SI inputs are converted first, see below). TC is total cholesterol, HDL is HDL cholesterol, TG is triglycerides, and non-HDL = TC − HDL.

Friedewald (1972), for TG under 400 mg/dL:

LDL = TC − HDL − TG ÷ 5

Sampson NIH equation 2 (2020), for TG up to 800 mg/dL:

LDL = TC ÷ 0.948 − HDL ÷ 0.971 − (TG ÷ 8.56 + TG × non-HDL ÷ 2140 − TG² ÷ 16100) − 9.44

Rules the page follows:

  1. HDL must be below total cholesterol; otherwise there is no answer.
  2. Friedewald gives no answer when TG is 400 mg/dL or more. Sampson gives no answer when TG is over 800 mg/dL.
  3. An estimate of 0 or less gives no answer.
  4. The page works with the exact decimals you typed and rounds once at the end, halves away from zero: LDL and non-HDL to a whole mg/dL, the mmol/L values to 2 decimals.
  5. The category is the NCEP ATP III band of the whole mg/dL value: under 100 optimal; 100 to 129 near or above optimal; 130 to 159 borderline high; 160 to 189 high; 190 or more very high.

Units. Cholesterol in mmol/L = mg/dL × 0.02586 (1 ÷ 38.67, the factor this site uses for cholesterol on every page). Triglycerides in mmol/L = mg/dL × 0.0113 (Sampson 2020). A value typed in mmol/L is divided by its factor to get mg/dL, the equation runs in mg/dL, and the LDL and non-HDL results are multiplied by 0.02586 for mmol/L. In mmol/L, the Friedewald limit of 400 mg/dL is 4.52 and the Sampson limit of 800 mg/dL is 9.04.

Worked examples by hand

Page default (Friedewald). TC 200, HDL 50, TG 150 mg/dL. LDL = 200 − 50 − 30 = 120 mg/dL, near or above optimal. In mmol/L: 120 × 0.02586 = 3.1032, 3.10. Non-HDL = 150 mg/dL, 150 × 0.02586 = 3.879, 3.88 mmol/L.

Same panel (Sampson). 200 ÷ 0.948 = 210.9705; 50 ÷ 0.971 = 51.4933; TG ÷ 8.56 = 17.5234; 150 × 150 ÷ 2140 = 10.5140; 150² ÷ 16100 = 1.3975. LDL = 210.9705 − 51.4933 − (17.5234 + 10.5140 − 1.3975) − 9.44 = 123.3973, 123 mg/dL; × 0.02586 = 3.191, 3.19 mmol/L.

High triglycerides (Sampson). TC 260, HDL 35, TG 500. 260 ÷ 0.948 = 274.2616; 35 ÷ 0.971 = 36.0453; 500 ÷ 8.56 = 58.4112; 500 × 225 ÷ 2140 = 52.5701; 500² ÷ 16100 = 15.5280. LDL = 274.2616 − 36.0453 − (58.4112 + 52.5701 − 15.5280) − 9.44 = 133.3229, 133 mg/dL, borderline high; 3.45 mmol/L. Friedewald gives no answer here (TG 500).

Borderline high (Friedewald). TC 240, HDL 40, TG 300. LDL = 240 − 40 − 60 = 140 mg/dL, borderline high; 140 × 0.02586 = 3.62 mmol/L. Non-HDL 200 mg/dL.

SI units (Friedewald). TC 5.2, HDL 1.3, TG 1.7 mmol/L. In mg/dL: 5.2 ÷ 0.02586 = 201.0828; 1.3 ÷ 0.02586 = 50.2707; 1.7 ÷ 0.0113 = 150.4425. LDL = 201.0828 − 50.2707 − 30.0885 = 120.7236, 121 mg/dL; × 0.02586 = 3.1219, 3.12 mmol/L. Non-HDL = 3.9 mmol/L exactly (5.2 − 1.3), 3.90.

Other questions people ask

How is LDL cholesterol calculated?

Most lab reports estimate it. The Friedewald equation takes total cholesterol, subtracts HDL cholesterol, and subtracts triglycerides ÷ 5 (all in mg/dL). The newer Sampson (NIH) equation uses the same three values with a different formula.

Which equation should I pick?

Friedewald is the classic equation and does not apply when triglycerides are 400 mg/dL or more. Sampson et al. (2020) found their NIH equation 2 more accurate than Friedewald, with good results for triglycerides up to 800 mg/dL.

What is a good LDL cholesterol level?

The NCEP ATP III report grades LDL under 100 mg/dL as optimal, 100 to 129 as near or above optimal, 130 to 159 as borderline high, 160 to 189 as high, and 190 or more as very high. Your own goal depends on your overall risk.

Why does the page refuse triglycerides of 400 or more with Friedewald?

The equation treats triglycerides ÷ 5 as the cholesterol carried by very low density lipoproteins. That estimate fails when triglycerides are high, so labs do not report a Friedewald LDL then.

What is non-HDL cholesterol?

It is total cholesterol minus HDL cholesterol: all the cholesterol in particles other than HDL. The page shows it next to the LDL estimate.

Can I enter values in mmol/L?

Yes. Pick mmol/L. The page converts cholesterol with 0.02586 mmol/L per mg/dL and triglycerides with 0.0113 mmol/L per mg/dL, works the equation in mg/dL, and shows the result in both units.