Cholesterol Ratio Calculator
Your cholesterol ratio is a better predictor of heart disease risk than total cholesterol alone. This calculator takes your lipid panel results and computes both Total:HDL and LDL:HDL ratios, then categorises your cardiovascular risk.
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How It Works
The Total:HDL ratio is calculated by dividing your total cholesterol by your HDL cholesterol. A ratio below 3.5 is considered ideal, 3.5-5.0 is good, 5.0-6.0 is borderline, and above 6.0 is high risk. The LDL:HDL ratio divides LDL by HDL — ideal is below 2.5, good is 2.5-3.5, and above 3.5 indicates elevated risk. These ratios are used alongside absolute cholesterol numbers by Australian cardiologists to assess cardiovascular risk.
Quick Reference
| Measure | Ideal | Borderline | High Risk |
|---|---|---|---|
| Total Cholesterol | < 5.5 mmol/L | 5.5-6.5 mmol/L | > 6.5 mmol/L |
| HDL Cholesterol | > 1.5 mmol/L | 1.0-1.5 mmol/L | < 1.0 mmol/L |
| LDL Cholesterol | < 2.0 mmol/L | 2.0-3.5 mmol/L | > 3.5 mmol/L |
| Total:HDL Ratio | < 3.5 | 3.5-5.0 | > 5.0 |
| LDL:HDL Ratio | < 2.5 | 2.5-3.5 | > 3.5 |
| Triglycerides | < 1.5 mmol/L | 1.5-2.0 mmol/L | > 2.0 mmol/L |
| Non-HDL Cholesterol | < 3.8 mmol/L | 3.8-4.8 mmol/L | > 4.8 mmol/L |
| --- | --- | --- | --- |
| ApoB (advanced) | < 0.8 g/L | 0.8-1.0 g/L | > 1.0 g/L |
Australian Heart Foundation targets for adults at low-moderate cardiovascular risk. Targets may be lower for high-risk individuals.
Frequently Asked Questions
- What is a good cholesterol ratio?
- A Total:HDL ratio below 3.5 is ideal. The Heart Foundation considers below 4.5 as acceptable for most adults. Higher ratios indicate a greater proportion of harmful cholesterol relative to protective HDL cholesterol.
- What should my cholesterol levels be in Australia?
- Australian guidelines recommend total cholesterol below 5.5 mmol/L, LDL below 2.0 mmol/L, HDL above 1.0 mmol/L for men and above 1.3 mmol/L for women, and triglycerides below 2.0 mmol/L. However, individual targets may differ based on overall cardiovascular risk.
- How can I improve my cholesterol ratio?
- Increase HDL by exercising regularly, eating healthy fats (olive oil, nuts, avocado), and losing excess weight. Lower LDL by reducing saturated fat, increasing soluble fibre, and eating more plant sterols. Even modest changes can shift your ratio significantly.
- How often should I get a cholesterol test?
- The Heart Foundation recommends adults over 45 (or over 35 for Aboriginal and Torres Strait Islander peoples) get a lipid panel every 2 years as part of an absolute cardiovascular risk assessment. More frequent testing may be needed if you have risk factors.
How This Is Calculated
- Total Cholesterol
- = sum of all cholesterol in blood (mmol/L)
- HDL
- = high-density lipoprotein — "good" cholesterol (mmol/L)
- LDL
- = low-density lipoprotein — "bad" cholesterol (mmol/L)
The ratio matters more than total cholesterol alone because HDL is protective. A person with total cholesterol of 6.0 and HDL of 2.0 (ratio 3.0) has lower risk than someone with 5.0 total and HDL of 0.8 (ratio 6.25).
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Disclaimer
This calculator provides estimates for informational purposes only and should not be considered medical advice. Individual results may vary based on factors not captured by these formulas. Consult a healthcare professional before making changes to your diet or exercise routine, especially if you have any existing health conditions.