Lipid panel ratios
Cholesterol Ratio Calculator
Calculate total cholesterol/HDL, triglycerides/HDL, and LDL/HDL ratios from a lipid panel. Enter any three blood values to estimate the fourth, or enter all four measured results.
Blood cholesterol
Values are entered in mg/dL. At least three of the four numeric fields are required.
Optional only when the other three values are present. Example: 180.
HDL must be greater than zero because every ratio uses it as the denominator.
May be zero or greater. Leave blank only when the other three values are known.
May be zero or greater. Example: 100.
Cholesterol ratios
Ratios update from the current measured or estimated values. They are descriptive arithmetic summaries, not a diagnosis.
Total cholesterol divided by HDL; unitless when both are in the same concentration unit.
Calculated from mg/dL values.
LDL divided by HDL; unitless when both values use the same unit.
TC/HDL 3.00; TG/HDL 1.67; LDL/HDL 1.67.
Current lipid values
The table distinguishes laboratory values you entered from a value estimated using the four-part identity.
| Measurement | Value | Source |
|---|---|---|
| Total cholesterol | 180.00 mg/dL | Entered |
| HDL | 60.00 mg/dL | Entered |
| LDL | 100.00 mg/dL | Entered |
| Triglycerides | 100.00 mg/dL | Entered |
All four demonstration values are entered and satisfy the estimation identity exactly.
How to use the Cholesterol Ratio Calculator
What this calculator does
This calculator turns four common lipid-panel measurements into three arithmetic ratios: Cholesterol / HDL ratio, Triglycerides / HDL ratio, and LDL / HDL ratio. It can also estimate one missing lipid value when the other three are available by rearranging total cholesterol = HDL + LDL + 0.2 × triglycerides. That relationship is useful for calculation and education, but an estimated value is not the same thing as a directly measured laboratory result. The ratios likewise do not replace the individual lipid values, a clinician's interpretation, or a validated cardiovascular-risk assessment.
When to use it
Use the calculator when you want to check arithmetic from a lipid panel, compare the three commonly discussed ratios, understand how a change in HDL affects several ratios at once, or reconstruct one missing value for an educational example. It is also useful when a source reports the triglycerides/HDL ratio after converting both analytes to mmol/L, because triglycerides and cholesterol use different molar conversion factors. For the meaning of the underlying laboratory measures, see the CDC overview of total cholesterol, LDL, HDL, and triglycerides.
How to calculate
- The calculator opens with a complete demonstration panel: total cholesterol 180 mg/dL, HDL 60 mg/dL, LDL 100 mg/dL, and triglycerides 100 mg/dL. The three ratios are already calculated, and the Excel workbook is immediately available.
- Replace the demonstration values with your laboratory numbers in mg/dL. You may enter all four measurements, or leave exactly one numeric field blank when the other three are known. If one field is blank, the table marks the reconstructed value as Calculated.
- Use Show triglycerides / HDL ratio in mmol/L only when you specifically want that ratio calculated after molar conversion. The total-cholesterol/HDL and LDL/HDL ratios do not change under a common cholesterol-unit conversion.
- Read the three results and the Current lipid values table. The table's Measurement, Value, and Source columns show which concentrations were entered and which, if any, were estimated.
- Select Download Excel to export the current validated inputs and outputs. Select Reset to clear the demonstration and all calculated content; Excel export is then disabled until at least three valid lipid values are supplied again.
Input guide
Total cholesterol is an optional-only-if-derivable decimal concentration in mg/dL. Enter a positive value such as 180. Higher total cholesterol raises the total-cholesterol/HDL ratio when HDL is unchanged. Do not type a unit, percent sign, scientific notation, or decimal comma into the field. If it is the one missing value, the calculator estimates it from HDL, LDL, and triglycerides.
HDL – High-Density Lipoprotein is a positive mg/dL concentration and the denominator for all three ratios, so it must resolve to a value greater than zero. A realistic demonstration value is 60 mg/dL. With other values fixed, higher HDL lowers all three displayed ratios. Avoid entering zero, because division by zero is undefined.
LDL – Low-Density Lipoprotein accepts a nonnegative mg/dL value such as 100. Increasing LDL raises the LDL/HDL ratio and, when total cholesterol is being estimated, also raises that estimated total. If LDL is the single blank field, the calculator computes total – HDL – 0.2 × triglycerides and rejects the state if that would be negative.
TG – Triglycerides accepts a nonnegative mg/dL value such as 100. Increasing triglycerides raises the triglycerides/HDL ratio and contributes one-fifth of its mg/dL value to the estimation identity. If triglycerides are the missing value, the rearranged calculation is 5 × (total – HDL – LDL), and a negative derived result is rejected.
Show triglycerides / HDL ratio in mmol/L is an optional checkbox. Off means the ratio is triglycerides in mg/dL divided by HDL in mg/dL. On means triglycerides are divided by 88.57 to convert to mmol/L and HDL is divided by 38.67 before the ratio is taken. Because those conversion factors differ, this specific ratio changes numerically when the basis changes.
Output guide
Cholesterol / HDL ratio is total cholesterol divided by HDL and is displayed to two decimals. Triglycerides / HDL ratio is triglycerides divided by HDL on the selected mg/dL or mmol/L basis. LDL / HDL ratio is LDL divided by HDL. All three are calculations, not diagnoses or stand-alone treatment targets. The four summary pills repeat the three current ratios and the triglycerides/HDL unit basis. The Current lipid values table reports each analyte in mg/dL and identifies its source as Entered or Calculated.
Worked example
With the startup panel, total cholesterol is 180 mg/dL and HDL is 60 mg/dL, so the cholesterol/HDL ratio is 180 ÷ 60 = 3.00. Triglycerides are 100 mg/dL, giving 100 ÷ 60 = 1.67 on the mg/dL basis. LDL is 100 mg/dL, so LDL/HDL is also 1.67. The four lipid values are internally consistent with the estimation identity because 60 + 100 + 0.2 × 100 = 180. If you clear LDL while leaving the other three startup values unchanged, the calculator reconstructs LDL as 180 – 60 – 20 = 100 mg/dL and marks that table row as Calculated.
Learn more
Cholesterol ratios should be read alongside the underlying panel. The MedlinePlus guide to cholesterol levels and lipid panels explains how total cholesterol, LDL, HDL, non-HDL cholesterol, and triglycerides are interpreted in context. If you are reviewing personal test results, use the calculator as an arithmetic aid and discuss clinical meaning with a qualified health professional.
How the formulas work
The total-cholesterol/HDL and LDL/HDL calculations are simple same-unit ratios. Changing both numerator and denominator from mg/dL to mmol/L with the same cholesterol conversion factor leaves those ratios unchanged. Triglycerides are chemically different, so their mmol/L conversion factor differs from the factor used for cholesterol. That is why a triglycerides/HDL ratio reported from mmol/L values is not numerically identical to one reported from mg/dL values.
The four-part identity used to fill one missing value is closely related to the traditional Friedewald relationship for estimating LDL from total cholesterol, HDL, and triglycerides. Modern lipid practice can use direct LDL measurements and newer estimation equations in some settings, so this calculator deliberately labels reconstructed concentrations as calculated rather than presenting them as laboratory measurements. A detailed clinical discussion of lipid measurement and LDL estimation is available in the NCBI Endotext chapter on dyslipidemia management.
Interpreting a lipid panel responsibly
Lipid results are not interpreted from a single ratio alone. Age, blood pressure, smoking, diabetes, kidney disease, known cardiovascular disease, family history, and other factors can materially change prevention goals. The American Heart Association explanation of cholesterol results emphasizes LDL, HDL, triglycerides, and overall cardiovascular risk rather than treating one ratio as a diagnosis.
For calculation quality, use values from the same blood draw and confirm their units before entering them. If all four measured values are available, this calculator uses all four directly for the ratios and merely reports how closely they fit the estimation identity; it does not overwrite a laboratory result. If exactly one value is absent, the reconstructed concentration is an estimate generated from the other three. This distinction matters because direct measurements, laboratory methods, and estimation equations can differ.