TyG index calculator

The formula

The TyG index is the natural log of fasting triglycerides (mg/dL) times fasting glucose (mg/dL), divided by 2 (Guerrero-Romero 2010). If your lab reports mmol/L, we first convert to mg/dL: triglycerides times 88.57 and glucose times 18. For example, triglycerides of 150 mg/dL and glucose of 100 mg/dL give ln(150 × 100 ÷ 2) = ln(7,500) = 8.92.

The researchers built it because the insulin test is expensive and not available in many laboratories, while triglycerides and glucose are routine tests (Simental-Mendía 2008). In the first study, of 748 apparently healthy adults, they compared it with HOMA-IR, an insulin-based estimate (Simental-Mendía 2008). In the second, of 99 adults ranging from healthy people without obesity to people with type 2 diabetes, it was compared with the euglycemic-hyperinsulinemic clamp, the reference research test. The correlation was -0.681: a higher TyG index went with lower insulin sensitivity (Guerrero-Romero 2010).

Why there is no "normal" line here

The 2008 paper reported a best cut point of "Ln 4.65" for spotting insulin resistance, with 84.0% sensitivity and 45.0% specificity (Simental-Mendía 2008). The 2010 paper reported 4.68, with 96.5% sensitivity and 85.0% specificity (Guerrero-Romero 2010). Those numbers are not on the same scale as values from the formula as printed in the 2010 paper: reaching 4.68 would need triglycerides times glucose of about 216, for example triglycerides of 20 mg/dL with glucose of 11 mg/dL, far below real fasting results. So those cut points cannot be compared with your result, and we show your value without labelling it normal or high.

The National Institute of Diabetes and Digestive and Kidney Diseases says health care professionals may not test for insulin resistance, and that the test is used mainly in research studies (NIDDK). Insulin resistance often goes with a larger waist, high blood pressure and abnormal blood fats; see the metabolic syndrome criteria.

Not a diabetes test

Diabetes and prediabetes are diagnosed with an A1C, a fasting plasma glucose or an oral glucose tolerance test, not with the TyG index (ADA Standards 2026). Your fasting glucose on its own already tells you more for that question: see prediabetes ranges and next steps. Your triglyceride result has its own adult categories: see triglyceride levels. To see your overall chance of type 2 diabetes, take the diabetes risk test.

TyG index or HOMA-IR?

HOMA-IR also estimates insulin resistance, but it needs a fasting insulin result, which many routine panels do not include. If you have one, the HOMA-IR calculator uses your fasting insulin and glucose. Neither has a single agreed cutoff, and neither diagnoses diabetes. Fatty liver often goes with insulin resistance; the fatty liver index calculator also uses fasting triglycerides, with BMI, waist and GGT, and the lipid accumulation product pairs them with waist size, and the visceral adiposity index adds waist, BMI and HDL.

Getting the right numbers

Use triglycerides and glucose from the same fasting blood draw. For a fasting blood sugar test, NHLBI says to fast for 8 to 12 hours (NHLBI). The index was built on fasting results, so a non-fasting triglyceride result should not be used here.