TG/HDL Ratio Calculator

Calculate your triglyceride-to-HDL (TG/HDL) ratio from your lipid panel. The TG/HDL ratio has been studied as a simple surrogate associated with insulin resistance and atherogenic lipid patterns. Important: the published cutoffs are defined for mg/dL, so unit choice matters. Supports mg/dL and mmol/L. Informational reference, not a diagnostic test.

Units

Triglycerides

mg/dL

HDL cholesterol

mg/dL

TG/HDL Ratio (mg/dL basis)

The widely cited TG/HDL cutoffs are defined for mg/dL. When you enter mmol/L values, this tool converts both to mg/dL before forming the ratio so the published bands apply. The ratio is a research surrogate, not a diagnostic test. Discuss your result with a healthcare provider.

Tracking your lipids? See your triglyceride and HDL trends over time in the Health3 app.

What the TG/HDL Ratio Reflects

The triglyceride-to-HDL ratio divides your triglyceride level by your HDL cholesterol. It is one of the simplest lipid-derived numbers, and research has associated a high ratio with insulin resistance, an atherogenic "small dense LDL" pattern, and cardiometabolic risk. It is appealing because it needs only two values that appear on every lipid panel.

One crucial detail: the commonly cited thresholds were derived using mg/dL for both triglycerides and HDL. Because triglycerides and cholesterol convert to mmol/L with different factors (88.57 versus 38.67), the numeric ratio is roughly 2.3 times larger in mg/dL than the raw mmol/L ratio. This tool always forms the ratio on the mg/dL basis so the published bands apply, regardless of which unit you enter.

Formula: TG/HDL ratio = Triglycerides ÷ HDL (both in mg/dL)
mmol/L inputs are converted first: triglycerides × 88.57, HDL × 38.67.

Published Reference Context

Cutoffs vary by population and sex; the bands below are commonly cited research reference points on the mg/dL basis, not a diagnosis.

TG/HDL ratio (mg/dL)	Commonly cited orientation
Below 2	Often cited as favourable
2 – 3	Intermediate
Above 3	Often cited as a comparison point for an atherogenic or insulin-resistant pattern (some studies use 3.5)

Limitations

Population and sex dependence. The most useful cutoff differs between men and women and across ethnic groups; a fixed threshold can mislead.
Fasting matters. Triglycerides rise after meals, inflating the ratio. Use fasting values for the published bands.
Not a diagnosis. It is a surrogate, not a test for insulin resistance or heart disease.

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Frequently Asked Questions

What is the TG/HDL ratio?

The TG/HDL ratio is your triglyceride level divided by your HDL cholesterol, using mg/dL for both. Research has associated a high ratio with insulin resistance, small dense LDL, and cardiometabolic risk. It is a simple surrogate from a standard lipid panel, not a diagnostic test.

What is a good TG/HDL ratio?

On the mg/dL basis, a ratio below 2 is commonly cited as favourable, 2 to 3 as intermediate, and above 3 (some studies use 3.5) as a comparison point for an atherogenic or insulin-resistant pattern. Cutoffs differ by sex and population, so these are reference points, not personal targets.

Why does the unit (mg/dL vs mmol/L) matter so much?

Because triglycerides and cholesterol convert to mmol/L with different factors (88.57 vs 38.67), the raw mmol/L ratio is about 2.3 times smaller than the mg/dL ratio. The widely published cutoffs were derived in mg/dL, so this calculator converts mmol/L inputs to mg/dL before forming the ratio to keep the bands valid.

Do I need to fast for the TG/HDL ratio?

Yes, for the published cutoffs. Triglycerides rise after eating, which inflates the ratio. Use values from an 8 to 12 hour fast. HDL is stable, but the triglyceride component is sensitive to recent meals.

Is a high TG/HDL ratio a diagnosis of insulin resistance?

No. A high ratio is associated with insulin resistance in research, but it is a surrogate marker, not a diagnostic test. Diagnosing insulin resistance or related conditions requires glucose tolerance testing, HbA1c, and clinical evaluation. Use the ratio as one reference point and discuss it with your clinician.

Medical Disclaimer: The TG/HDL ratio is a research-derived lipid surrogate, not a diagnostic test. The commonly cited cutoffs are defined for mg/dL and vary by sex and population; they are reference points, not personal targets. This tool is for informational and educational use only and does not diagnose insulin resistance or cardiovascular disease. Always consult a qualified healthcare provider to interpret your lipid results.

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