# What are my cholesterol levels?

Reads a lipid panel: grades total cholesterol, HDL cholesterol, and triglycerides by NCEP ATP III, and estimates LDL cholesterol with the Sampson (NIH) equation.

- Page: https://www.acalculator.org/health/cholesterol-calculator
- JSON spec: https://www.acalculator.org/health/cholesterol-calculator.json
- Version: c7687158d427

## Default answer

Example with the default inputs (Units mg/dL, Total cholesterol (mg/dL) 200, HDL cholesterol (mg/dL) 50, Triglycerides (mg/dL) 150): The estimated LDL cholesterol is 123 mg/dL, Near or above optimal (100 to 129 mg/dL). Total cholesterol: Borderline high (200 to 239 mg/dL). HDL: Between the cut-offs (40 to 59 mg/dL). Triglycerides: Borderline high (150 to 199 mg/dL).

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| units | Units | US units (mg/dL) or SI units (mmol/L). |
| tc | Total cholesterol (mg/dL) | Total cholesterol, 50 to 1,000 mg/dL. |
| tcSi | Total cholesterol (mmol/L) | Total cholesterol, 1.3 to 25.9 mmol/L. |
| hdl | HDL cholesterol (mg/dL) | HDL ("good") cholesterol, 5 to 200 mg/dL. |
| hdlSi | HDL cholesterol (mmol/L) | HDL ("good") cholesterol, 0.13 to 5.17 mmol/L. |
| tg | Triglycerides (mg/dL) | Triglycerides, 10 to 3,000 mg/dL. |
| tgSi | Triglycerides (mmol/L) | Triglycerides, 0.11 to 33.9 mmol/L. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| ldl | LDL cholesterol (mg/dL) | LDL cholesterol estimated with the Sampson NIH equation 2, in mg/dL, to a whole number. |
| ldlSi | LDL cholesterol (mmol/L) | The same estimate in mmol/L (mg/dL × 0.02586), to 2 decimals. |
| ldlCategory | LDL | The ATP III band of the LDL estimate. |
| tcCategory | Total cholesterol | The ATP III band of total cholesterol. |
| hdlCategory | HDL cholesterol | The ATP III band of HDL cholesterol. |
| tgCategory | Triglycerides | The ATP III band of the triglycerides. |
| nonHdl | Non-HDL cholesterol (mg/dL) | Total cholesterol minus HDL cholesterol, in mg/dL, to a whole number. |
| ratio | Total to HDL ratio | Total cholesterol ÷ HDL cholesterol, to 1 decimal. |

## Method

LDL (Sampson NIH equation 2, mg/dL) = TC/0.948 − HDL/0.971 − (TG/8.56 + TG × non-HDL/2140 − TG²/16100) − 9.44, for TG up to 800. Non-HDL = TC − HDL. Ratio = TC ÷ HDL. Bands: NCEP ATP III.

## Assumptions

- Total cholesterol, HDL cholesterol, and triglycerides come from the same blood sample.
- Each band is read from the whole mg/dL value; SI values are converted with 0.02586 (cholesterol) and 0.0113 (triglycerides) mmol/L per mg/dL first.

## Worked examples

1. units = us, tc = 200, hdl = 50, tg = 150 gives ldl = 123, ldlSi = 3.19, ldlCategory = Near or above optimal (100 to 129 mg/dL), tcCategory = Borderline high (200 to 239 mg/dL), hdlCategory = Between the cut-offs (40 to 59 mg/dL), tgCategory = Borderline high (150 to 199 mg/dL), nonHdl = 150, ratio = 4. Source: Sampson 2020 NIH equation 2 = 123.397 mg/dL.
2. units = us, tc = 180, hdl = 60, tg = 100 gives ldl = 102, ldlCategory = Near or above optimal (100 to 129 mg/dL), tcCategory = Desirable (under 200 mg/dL), hdlCategory = High (60 mg/dL or more), tgCategory = Normal (under 150 mg/dL), ratio = 3. Source: Sampson 2020 NIH equation 2 = 101.973 mg/dL.
3. units = us, tc = 260, hdl = 35, tg = 500 gives ldl = 133, tcCategory = High (240 mg/dL or more), hdlCategory = Low (under 40 mg/dL), tgCategory = Very high (500 mg/dL or more), nonHdl = 225, ratio = 7.4. Source: Sampson 2020 NIH equation 2 = 133.323 mg/dL.
4. units = si, tcSi = 5.2, hdlSi = 1.3, tgSi = 1.7 gives ldl = 124, ldlSi = 3.21, tcCategory = Borderline high (200 to 239 mg/dL), tgCategory = Borderline high (150 to 199 mg/dL), ratio = 4. Source: Sampson 2020 NIH equation 2 = 124.129 mg/dL, × 0.02586 = 3.210 mmol/L.

## FAQ

### What is a normal total cholesterol level?

The NCEP ATP III report calls total cholesterol under 200 mg/dL desirable, 200 to 239 borderline high, and 240 or more high.

### What HDL cholesterol level is good?

ATP III calls HDL under 40 mg/dL low, a risk factor for heart disease, and 60 or more high, which counts against risk. Values from 40 to 59 sit between the two cut-offs.

### What are normal triglycerides?

ATP III grades triglycerides under 150 mg/dL as normal, 150 to 199 as borderline high, 200 to 499 as high, and 500 or more as very high.

### How does the page get LDL cholesterol?

It uses the Sampson (NIH) equation 2 from 2020, which works from total cholesterol, HDL cholesterol, and triglycerides and was checked for triglycerides up to 800 mg/dL. The LDL calculator also offers the older Friedewald equation.

### What is non-HDL cholesterol?

Total cholesterol minus HDL cholesterol. It counts the cholesterol in every particle except HDL.

### Do I need to fast before a cholesterol test?

Ask the lab or your clinician. The Sampson equation was derived from fasting samples.

## Sources

- Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive summary of the third report of the National Cholesterol Education Program (NCEP) Adult Treatment Panel III. JAMA. 2001;285(19):2486-2497. https://doi.org/10.1001/jama.285.19.2486 (retrieved 2026-10-05)
- Sampson M, Ling C, Sun Q, et al. A new equation for calculation of low-density lipoprotein cholesterol in patients with normolipidemia and/or hypertriglyceridemia. JAMA Cardiol. 2020;5(5):540-548. https://doi.org/10.1001/jamacardio.2020.0013 (open at https://pmc.ncbi.nlm.nih.gov/articles/PMC7240357/, retrieved 2026-10-05)
- The NIH equation 2 written out in text: Assessing the practical differences in LDL-C estimates calculated by Friedewald, Martin/Hopkins, or NIH equation 2. https://pmc.ncbi.nlm.nih.gov/articles/PMC10548185/ (retrieved 2026-10-05)
- Nelson RH. Hyperlipidemia as a risk factor for cardiovascular disease. Prim Care. 2013;40(1):195-211. Table 1 reproduces the ATP III classification of LDL, total, and HDL cholesterol and triglycerides. https://pmc.ncbi.nlm.nih.gov/articles/PMC3572442/ (retrieved 2026-10-05)