Calculate a ratio from mmol/L values
Total 5.0 ÷ HDL 1.25 = 4.00
Non-HDL: 5.0 − 1.25 = 3.75 mmol/L
Heart health calculator
Total cholesterol to HDL ratio and non-HDL calculator
Enter total cholesterol and HDL cholesterol to calculate the total-to-HDL ratio and non-HDL cholesterol. Mixed mmol/L and mg/dL inputs are normalised safely before calculation.
Private by design
Calculations happen on this device. Nothing you enter is sent to or stored by Trupoint.
Enter a laboratory result
Not stored
Cholesterol ratio calculator
Educational conversion only. Laboratory ranges vary, and unexpected results should be discussed with a qualified clinician.
Three simple steps
How to use this calculator
Use the wording and unit from your original laboratory report. Keep that report available when reviewing the converted value.
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1
Enter total cholesterol
Copy the total cholesterol value and its unit from the same lipid report you will use for HDL.
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2
Enter HDL cholesterol
Copy the HDL value and select its unit. The calculator safely normalises mixed units before calculating.
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3
Review both calculated values
The output gives the unitless total-to-HDL ratio plus non-HDL cholesterol in mmol/L and mg/dL.
How it works
About this calculation
The total-to-HDL ratio expresses total cholesterol relative to HDL. Non-HDL cholesterol represents total cholesterol minus HDL and includes several cholesterol-carrying particles. These values are components of cardiovascular assessment, not standalone diagnoses.
Worked answers
Conversion examples and common values
These examples show the arithmetic and the rounding used by the calculator. They are not reference ranges or personal targets.
Calculate from another same-unit pair
Total 4.5 ÷ HDL 1.5 = 3.00
Non-HDL: 4.5 − 1.5 = 3.00 mmol/LUse mixed units safely
Total 193 mg/dL is normalised to 4.99 mmol/L before division by HDL 1.25 mmol/L
Displayed ratio: approximately 3.99| Total cholesterol | HDL cholesterol | Total:HDL ratio | Non-HDL |
|---|---|---|---|
| 4.5 mmol/L | 1.5 mmol/L | 3.00 | 3.00 mmol/L |
| 5.0 mmol/L | 1.25 mmol/L | 4.00 | 3.75 mmol/L |
| 5.5 mmol/L | 1.1 mmol/L | 5.00 | 4.40 mmol/L |
| 193.35 mg/dL | 48.34 mg/dL | 4.00 | 145 mg/dL |
What the ratio and non-HDL calculation represent
The total-to-HDL ratio compares total cholesterol with the HDL portion. Because both inputs are concentrations of cholesterol, the ratio has no unit once they are expressed on the same scale.
Non-HDL cholesterol subtracts HDL from total cholesterol. It therefore includes cholesterol carried in LDL and other non-HDL particles. It is not the same value as LDL cholesterol and should not be substituted for LDL on a report.
Important context
Limitations
The calculated values do not estimate your personal chance of heart attack or stroke. Cardiovascular assessment also considers factors including age, blood pressure, smoking, diabetes, family history and existing conditions.
Questions about this tool
Frequently asked questions
These answers explain the calculation and its limitations. They do not interpret an individual laboratory result.
How is the total cholesterol to HDL ratio calculated?
Divide total cholesterol by HDL cholesterol after expressing both values in the same unit. The resulting ratio itself has no unit.
How is non-HDL cholesterol calculated?
Subtract HDL cholesterol from total cholesterol. The answer keeps the same concentration unit as the two input values.
Can I enter total cholesterol and HDL in different units?
Yes. This calculator converts both inputs to a common internal unit before calculating the ratio and non-HDL values. Check each selector carefully.
Is non-HDL cholesterol the same as LDL cholesterol?
No. Non-HDL is total cholesterol minus HDL and includes LDL plus cholesterol carried in other non-HDL particles.
Does the cholesterol ratio calculate my risk of heart disease?
No. It supplies two mathematical values used within broader assessment. Personal cardiovascular risk also depends on factors such as age, blood pressure, smoking, diabetes, family history and existing conditions.
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