Cholesterol Ratio Calculator
Turn the numbers from your lipid panel into the ratios doctors look at: total cholesterol to HDL, LDL to HDL and triglycerides to HDL, plus non-HDL cholesterol. Works in mg/dL or mmol/L and can estimate LDL if it is missing.
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Leave blank to estimate it from TC, HDL and triglycerides
How to use the Cholesterol Ratio Calculator
- Pick the units printed on your lab report (mg/dL or mmol/L).
- Enter total cholesterol and HDL, the two values every ratio needs.
- Add LDL and triglycerides. Leave LDL blank to estimate it.
- Read the TC/HDL ratio and the other ratios with their categories.
- Check the table to compare each value with the desirable range.
Cholesterol ratio formulas
- TC/HDL = total cholesterol ÷ HDL
- LDL/HDL = LDL ÷ HDL
- TG/HDL = triglycerides ÷ HDL (both in mg/dL)
- Non-HDL = total cholesterol − HDL
- Friedewald LDL = TC − HDL − TG ÷ 5 (mg/dL) or TC − HDL − TG ÷ 2.2 (mmol/L)
Example: total 200, HDL 50, LDL 120, triglycerides 150 mg/dL gives TC/HDL 4.0, LDL/HDL 2.4, TG/HDL 3.0 and non-HDL 150 mg/dL.
Reference ranges for adults
| Measure | Desirable | Borderline | High |
|---|---|---|---|
| Total cholesterol | < 200 mg/dL (< 5.2 mmol/L) | 200–239 (5.2–6.2) | ≥ 240 (≥ 6.2) |
| LDL | < 100 mg/dL (< 2.6 mmol/L) | 130–159 (3.4–4.1) | ≥ 160 (≥ 4.1) |
| HDL | ≥ 60 mg/dL (≥ 1.55 mmol/L) | 40–59 (men), 50–59 (women) | Low: < 40 men, < 50 women |
| Triglycerides | < 150 mg/dL (< 1.7 mmol/L) | 150–199 (1.7–2.2) | ≥ 200 (≥ 2.3) |
| Non-HDL | < 130 mg/dL (< 3.4 mmol/L) | 130–189 | ≥ 190 (≥ 4.9) |
| TC/HDL ratio | < 3.5 | 3.5–5.0 | > 5.0 |
| LDL/HDL ratio | < 2.5 | 2.5–3.5 | > 3.5 |
| TG/HDL ratio (mg/dL) | < 2 | 2–4 | > 4 |
Lipid ranges follow the US NCEP ATP III categories; ratio targets are commonly used guide values. LDL of 100–129 mg/dL is called "near optimal", and 190 mg/dL or more is "very high".
Tips for reading your results
- Use values from the same blood test; mixing reports from different dates distorts ratios.
- Triglycerides rise after meals, so they are most reliable from a fasting sample or a consistent routine.
- A low ratio driven by a very high HDL is not automatically protective; your doctor looks at the whole picture.
Frequently asked questions
What is a good cholesterol ratio?
For total cholesterol divided by HDL, under 5 is generally considered acceptable and under 3.5 is optimal. For example, a total of 200 mg/dL with an HDL of 50 gives a ratio of 4.0.
How do I calculate my cholesterol ratio?
Divide your total cholesterol by your HDL cholesterol, using the same units for both. The result has no units, so it is the same whether your report uses mg/dL or mmol/L.
What does the triglyceride to HDL ratio mean?
TG/HDL is used as a rough marker of insulin resistance and of small, dense LDL particles. Calculated in mg/dL, a value under 2 is considered ideal and over 4 high. In mmol/L the same cutoffs are about 0.9 and 1.7, so this calculator always uses the mg/dL basis.
What is non-HDL cholesterol?
Non-HDL cholesterol is total cholesterol minus HDL. It includes LDL and other particles that can build up in arteries. Under 130 mg/dL (about 3.4 mmol/L) is desirable for most adults.
How is LDL estimated if my report does not show it?
The Friedewald formula estimates LDL as total cholesterol − HDL − triglycerides ÷ 5 in mg/dL (÷ 2.2 in mmol/L). It is not valid when triglycerides are 400 mg/dL or higher; then a direct LDL measurement is needed.
How do I convert cholesterol from mmol/L to mg/dL?
Multiply cholesterol values (total, LDL, HDL) by 38.67 and triglycerides by 88.57. For example, 5.2 mmol/L of total cholesterol is about 201 mg/dL.
Are ratios more important than LDL?
Current guidelines mainly use LDL and non-HDL to set treatment goals, together with your overall heart risk. Ratios add useful context, especially when HDL is very high or very low. Always discuss your results with a health professional.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.