Cholesterol Ratio Calculator: TC/HDL and LDL/HDL Ratios
Cholesterol ratios give clinicians and patients a more nuanced picture of cardiovascular risk than total cholesterol alone. The TC/HDL ratio (total cholesterol divided by HDL) is widely regarded by the American Heart Association as a reliable predictor of heart disease risk because it balances the harmful LDL-driven cholesterol against the protective HDL cholesterol in a single figure. A low ratio means a higher proportion of your cholesterol is the beneficial HDL type. The LDL/HDL ratio adds further precision by focusing specifically on the balance between the primary atherogenic lipoprotein (LDL) and protective HDL. Non-HDL cholesterol, calculated by subtracting HDL from total cholesterol, captures all atherogenic particles including VLDL and IDL and does not require fasting. The optional triglyceride/HDL ratio is used in research as a marker of insulin resistance and small, dense LDL. To use this calculator, enter the values from your most recent fasting lipid panel. All inputs are in milligrams per deciliter (mg/dL), the standard US measurement unit for lipid panels. The primary result is your TC/HDL ratio with its AHA risk category. Results should always be discussed with a healthcare provider in the context of your full clinical history, not used alone to diagnose or treat any condition.
Your TC/HDL ratio is -- (--). LDL/HDL ratio: -- (--).
How cholesterol ratios are calculated
All four metrics are derived directly from a standard lipid panel. The formulas below use mg/dL values as reported by US laboratories.
TC/HDL ratio = Total Cholesterol / HDL
LDL/HDL ratio = LDL / HDL
Non-HDL cholesterol (mg/dL) = Total Cholesterol - HDL
Triglyceride/HDL ratio = Triglycerides / HDL
Worked example
Total cholesterol 200 mg/dL, HDL 55 mg/dL, LDL 120 mg/dL, triglycerides 130 mg/dL (male):
- TC/HDL = 200 / 55 = 3.64 (Acceptable range)
- LDL/HDL = 120 / 55 = 2.18 (Optimal for men: below 2.5)
- Non-HDL = 200 - 55 = 145 mg/dL (Borderline: 130 to 159)
- Trig/HDL = 130 / 55 = 2.36
TC/HDL risk categories (AHA)
| TC/HDL Ratio | Risk Category |
|---|---|
| Below 3.5 | Optimal |
| 3.5 to 5.0 | Acceptable |
| Above 5.0 | Increased cardiovascular risk |
LDL/HDL risk categories (AHA)
| LDL/HDL Ratio | Men | Women |
|---|---|---|
| Optimal | Below 2.5 | Below 2.0 |
| Acceptable | 2.5 to 3.5 | 2.0 to 3.0 |
| Increased risk | Above 3.5 | Above 3.0 |
Non-HDL cholesterol categories (NHLBI)
| Non-HDL (mg/dL) | Category |
|---|---|
| Below 130 | Optimal |
| 130 to 159 | Borderline high |
| 160 and above | High |
Understanding your cholesterol numbers
HDL cholesterol is often called "good" cholesterol because it helps transport excess cholesterol from the arteries back to the liver for processing. Higher HDL values are protective. LDL cholesterol is often called "bad" cholesterol because elevated levels contribute to plaque build-up in artery walls (atherosclerosis), raising the risk of heart attack and stroke.
Ratios provide context. A person with total cholesterol of 240 mg/dL but HDL of 80 mg/dL has a TC/HDL ratio of 3.0, which is optimal. A person with total cholesterol of 180 mg/dL but HDL of only 30 mg/dL has a TC/HDL ratio of 6.0, which signals increased risk. This is why ratios are often more clinically informative than any single value.
Lifestyle factors that improve ratios include regular aerobic exercise, quitting smoking, reducing trans fats and refined carbohydrates, increasing dietary fibre, and maintaining a healthy weight. Medications such as statins, fibrates, and niacin may also be prescribed by a healthcare provider when lifestyle changes are insufficient.
Cholesterol ratio calculator: frequently asked questions
What is the TC/HDL cholesterol ratio and why does it matter?
The TC/HDL ratio divides total cholesterol by HDL (good) cholesterol. A lower number is better because it indicates more of your total cholesterol is the protective HDL type. The American Heart Association considers a ratio below 3.5 optimal, 3.5 to 5.0 acceptable, and above 5.0 a sign of increased cardiovascular risk. Many clinicians regard this ratio as a stronger predictor of heart disease risk than total cholesterol alone.
What is a healthy LDL/HDL ratio?
The optimal LDL/HDL ratio differs slightly by sex. For men, a ratio below 2.5 is considered optimal and below 3.5 is acceptable. For women, below 2.0 is optimal and below 3.0 is acceptable. Ratios above these thresholds may indicate increased cardiovascular risk and should be discussed with a healthcare provider who can consider your full clinical picture.
What is non-HDL cholesterol and how is it calculated?
Non-HDL cholesterol is simply total cholesterol minus HDL cholesterol. It captures all the atherogenic (plaque-forming) lipoproteins in a single number, including LDL, VLDL, IDL, and lipoprotein(a). The NHLBI considers non-HDL below 130 mg/dL optimal, 130 to 159 mg/dL borderline, and 160 mg/dL or above high. Non-HDL does not require a fasting blood draw, making it a convenient screening measure.
What does the triglyceride/HDL ratio indicate?
The triglyceride/HDL ratio is used as a surrogate marker for insulin resistance and small, dense LDL particles. A ratio below 2.0 is generally considered low risk, and above 4.0 may indicate elevated cardiovascular risk in some research studies. However, this ratio is not as firmly established in clinical guidelines as TC/HDL or LDL/HDL, and its interpretation varies by ethnicity and metabolic status.
Can I use this calculator without a full lipid panel?
You need at minimum total cholesterol and HDL from a blood test to calculate the TC/HDL ratio. LDL is needed for the LDL/HDL ratio. Triglycerides are optional; enter them only if your panel includes them. Values entered should be from a laboratory lipid panel, not estimated. Always obtain your lipid values through a qualified healthcare provider and interpret results in the context of your overall health history.
Official sources
- American Heart Association: About Cholesterol.
- National Heart, Lung, and Blood Institute: Blood Cholesterol.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology. General information only, not medical advice.