The four numbers on a lipid panel
- Total cholesterol: all the cholesterol carried in the blood.
- HDL ("good" cholesterol): carries cholesterol back to the liver. Higher is generally better.
- LDL ("bad" cholesterol): the main driver of plaque in the arteries and the usual treatment target.
- Triglycerides: a type of fat that rises after meals and with excess sugar, alcohol and weight.
Many laboratories do not measure LDL directly. They calculate it from the other three values, which is what this calculator does when you leave the LDL field empty.
Formulas used
LDL (mg/dL) ≈ total − HDL − triglycerides ÷ 5
LDL (mmol/L) ≈ total − HDL − triglycerides ÷ 2.2
Non-HDL = total − HDL
Ratio = total ÷ HDL
The first two lines are the Friedewald formula (1972). It works well when triglycerides are below 400 mg/dL (4.5 mmol/L), ideally from a fasting sample. Above that, or when LDL is very low, labs use a direct measurement or newer equations such as Martin–Hopkins or Sampson, so the calculator warns you instead of estimating.
To convert units: cholesterol (total, HDL, LDL) mmol/L × 38.67 = mg/dL; triglycerides mmol/L × 88.57 = mg/dL.
Adult categories
These cut-offs come from the U.S. National Cholesterol Education Program (ATP III) and are still widely printed on lab reports. Treatment targets today depend on your overall cardiovascular risk rather than on these categories alone.
| Measure | Desirable | Borderline | High |
|---|---|---|---|
| Total cholesterol | below 200 mg/dL (5.2) | 200–239 (5.2–6.2) | 240 or more (6.2+) |
| LDL | below 100 optimal, 100–129 near optimal | 130–159 | 160–189 high, 190+ very high |
| HDL | 60 or more (1.55+) protective | 40–59 | below 40 (1.0) is low |
| Triglycerides | below 150 (1.7) | 150–199 | 200–499 high, 500+ very high |
Worked examples
| Total | HDL | Triglycerides | LDL (Friedewald) | Non-HDL | Total/HDL |
|---|---|---|---|---|---|
| 180 | 60 | 100 | 100 | 120 | 3.0 |
| 200 | 50 | 150 | 120 | 150 | 4.0 |
| 220 | 45 | 180 | 139 | 175 | 4.9 |
| 240 | 40 | 250 | 150 | 200 | 6.0 |
All values in mg/dL. In mmol/L, the second row is about 5.17 total, 1.29 HDL and 1.69 triglycerides, giving an LDL of about 3.1 mmol/L.
Why non-HDL cholesterol matters
Non-HDL cholesterol includes LDL plus the other particles that can build up in artery walls. It does not need a fasting sample and stays reliable when triglycerides are high, so many guidelines, including the European ones, use it as a secondary target. A rough rule: the non-HDL goal is about 30 mg/dL (0.8 mmol/L) above the LDL goal.
The total/HDL ratio
Dividing total cholesterol by HDL gives a single number used in some risk calculators. Lower is better; a ratio below about 5 is commonly described as acceptable and below about 3.5 as ideal. The ratio is a convenient summary, but doctors still look at LDL and non-HDL separately because they guide treatment.
Improving your numbers
- Swap saturated fat for unsaturated fat: less fatty meat, butter and palm-oil snacks; more fish, nuts, olive or canola oil.
- Eat more soluble fibre from oats, beans, lentils and fruit.
- Cut sugar, refined carbohydrates and alcohol, which raise triglycerides.
- Move regularly; aerobic exercise raises HDL modestly and lowers triglycerides.
- Stop smoking, which lowers HDL and damages arteries.
When LDL is very high (190 mg/dL or 4.9 mmol/L and above) or cardiovascular risk is high, lifestyle changes alone are usually not enough, and medicines such as statins are considered.
Common mistakes
- Mixing units, for example HDL in mmol/L and total in mg/dL.
- Using the Friedewald estimate with very high triglycerides, which underestimates LDL.
- Comparing a non-fasting result with a fasting one; triglycerides can be noticeably higher after a meal.
This calculator explains numbers for adults and is not a diagnosis or a treatment recommendation. Discuss your results and overall heart risk with a health professional.
When and how to get tested
The American Heart Association suggests that healthy adults have their cholesterol checked every four to six years from age 20, and more often with risk factors such as diabetes, high blood pressure, smoking or a family history of early heart disease. Many guidelines also recommend at least one test in childhood or adolescence to catch inherited high cholesterol (familial hypercholesterolaemia), which affects roughly 1 in 250 people.
Most labs now accept a non-fasting sample for routine checks, because total, HDL and non-HDL cholesterol change little after a meal. Your doctor may still ask you to fast if a previous triglyceride result was high, since triglycerides rise after eating.
Frequently asked questions
How is LDL calculated?
With the Friedewald formula: LDL = total cholesterol − HDL − triglycerides ÷ 5 in mg/dL (÷ 2.2 in mmol/L). It is valid when triglycerides are below 400 mg/dL.
What is a good cholesterol ratio?
Total cholesterol divided by HDL below about 5 is commonly called acceptable, and below about 3.5 ideal.
What is non-HDL cholesterol?
Total cholesterol minus HDL. It counts all potentially harmful cholesterol particles and does not require fasting.
How do I convert cholesterol from mmol/L to mg/dL?
Multiply by 38.67 for total, HDL and LDL cholesterol, and by 88.57 for triglycerides.
Do I need to fast before a cholesterol test?
Usually not for a routine check. Fasting may be requested if your triglycerides were previously high.
Sources
- National Cholesterol Education Program. Third Report of the Expert Panel (ATP III), NIH, 2002.
- Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of LDL cholesterol in plasma. Clinical Chemistry, 1972.
- Grundy SM et al. 2018 AHA/ACC Guideline on the Management of Blood Cholesterol. Circulation, 2019.
- Mach F et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias. European Heart Journal, 2020.
Last reviewed 7 October 2026. Results are estimates; see our disclaimer.