TyG Index Calculator

Compute the triglyceride-glucose (TyG) index from your fasting triglycerides and fasting glucose using the published natural-log formula. TyG is a surrogate marker studied as a low-cost alternative to insulin testing for estimating insulin resistance. Supports mg/dL and mmol/L inputs. This is an informational reference, not a diagnostic test.

Units

Fasting triglycerides

mg/dL

Fasting glucose

mg/dL

TyG Index

TyG is a published research surrogate, not a diagnostic test. No single universal cutoff exists; many studies use about 8.5 as a comparison point. Both triglycerides and glucose must be measured fasting. Discuss your result with a healthcare provider.

Tracking your metabolic markers? See your triglyceride and glucose trends over time in the Health3 app.

What the TyG Index Measures

The triglyceride-glucose (TyG) index is a simple number derived from two values found on almost every routine blood panel: fasting triglycerides and fasting glucose. It was proposed by Simental-Mendía and colleagues in 2008 (Metabolic Syndrome and Related Disorders 6:299–304) as an inexpensive surrogate for insulin resistance, because direct insulin assays were costly and not available everywhere. Since then it has been studied as a marker associated with insulin resistance, metabolic syndrome, and incident type 2 diabetes in many cohorts.

The idea is that when tissues respond less efficiently to insulin, fasting glucose and triglycerides both tend to drift upward, so their product carries a metabolic signal. Unlike HOMA-IR, TyG does not require an insulin measurement, which makes it cheaper to compute from standard labs.

Formula (Simental-Mendía et al., 2008):
TyG = ln[ Triglycerides (mg/dL) × Glucose (mg/dL) ÷ 2 ]
Both values fasting and in mg/dL. mmol/L inputs are converted to mg/dL first (triglycerides × 88.57, glucose × 18.016).

Published Reference Context

There is no single agreed cutoff for TyG, and the typical numeric range depends on the exact formula used. With the natural-log form above, values in adults usually fall between about 8.0 and 9.5. Many studies use a threshold of around 8.5 as a comparison point for higher likelihood of insulin resistance, but the optimal value varies by population, sex, age, and outcome. The bands below are a general orientation drawn from the published literature, not a diagnosis.

TyG Index	General published orientation
Below 8.5	Below the threshold most commonly used as a comparison point
8.5 – 9.0	Around or above the commonly cited comparison thresholds
Above 9.0	Toward the higher end of commonly reported values

Limitations

Not a diagnosis. TyG is a research surrogate. It does not diagnose insulin resistance, prediabetes, or diabetes, which require glucose tolerance testing, HbA1c, and clinical evaluation.
Fasting is required. A recent meal raises both triglycerides and glucose and inflates the score. Use values from an 8–12 hour fast.
Population dependence. The most useful cutoff differs across ethnic groups and studies, so a fixed threshold can mislead.

Explore Related Topics

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Frequently Asked Questions

What is the TyG index?

The triglyceride-glucose (TyG) index is a number calculated from fasting triglycerides and fasting glucose, proposed by Simental-Mendia et al. in 2008 as a low-cost surrogate for insulin resistance. It is computed as the natural log of (triglycerides x glucose / 2), both in mg/dL. It is a research marker, not a diagnostic test.

What is a normal TyG index?

There is no single universal cutoff. With the natural-log formula used here, adult values usually fall between about 8.0 and 9.5, and many studies use a threshold of around 8.5 as a comparison point for higher likelihood of insulin resistance. Because the most useful threshold differs across populations, the TyG index is best read as one data point alongside your full clinical picture, not against a fixed normal range.

How is TyG different from HOMA-IR?

Both estimate insulin resistance, but HOMA-IR needs a fasting insulin measurement, while TyG uses only fasting triglycerides and glucose, which appear on standard lipid and metabolic panels. That makes TyG cheaper to compute. Neither is a diagnostic test, and the two do not always agree in the same person.

Do I need to fast for the TyG index?

Yes. Both triglycerides and glucose must be measured after an 8 to 12 hour overnight fast. Food raises both values and would inflate the score. Water is fine during the fast. If you are not sure your values were taken fasting, do not use them in this calculator.

Can I enter mmol/L values?

Yes. Switch the unit toggle to mmol/L and the calculator converts triglycerides and glucose to mg/dL before applying the formula (triglycerides x 88.57, glucose x 18.016), since the published TyG formula is defined in mg/dL.

Medical Disclaimer: The TyG index is a published research surrogate for insulin resistance, not a diagnostic test. It cannot diagnose insulin resistance, prediabetes, type 2 diabetes, or metabolic syndrome, and no single cutoff applies to all populations. This tool is for general informational and educational use only. Based on Simental-Mendía LE, et al. Metab Syndr Relat Disord. 2008;6(4):299–304. Always consult a qualified healthcare provider to interpret your results.

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