TyG Index Calculator

The TyG (Triglyceride-Glucose) index is a surrogate marker for insulin resistance. It captures the combined behavior of two metabolic signals — fasting triglycerides and fasting glucose — that both rise when the body is producing more insulin than it should to clear carbohydrates and fat from the bloodstream. A higher TyG index indicates a metabolic state consistent with insulin resistance, even when fasting insulin is not on the lab panel.

HOMA-IR is the more direct measure when fasting insulin is available — it uses fasting insulin and fasting glucose directly. TyG is a surrogate that uses fasting triglycerides as a proxy for the insulin signal, which works because chronically elevated insulin drives the liver to produce more triglycerides. TyG is most useful when fasting insulin is not on a standard lab panel; the HOMA-IR Calculator is preferred when both insulin and glucose are available.

A TyG index below 8.0 is the Lower Risk band — consistent with insulin sensitivity in most populations. The range 8.0 to 8.8 is the Moderate Risk band, where early insulin resistance often appears years before fasting glucose itself rises out of range. A TyG above 8.8 is the Higher Risk band and strongly suggests insulin resistance worth investigating with a fuller metabolic workup. A single elevated value is directional, not diagnostic — triglycerides are sensitive to recent meals and individual variation is significant.

TyG = ln(Triglycerides [mg/dL] × Glucose [mg/dL] / 2). Values in mmol/L are converted before the calculation: triglycerides multiplied by 88.57 and glucose multiplied by 18.018 to reach mg/dL. The natural-log transformation is what compresses the index into the roughly 7.0 to 10.0 range used by the published cut-points.

Metformin lowers fasting glucose, and statins or fibrates lower triglycerides — both directly affect the inputs to TyG. The calculated index may underestimate the underlying insulin-resistance load if either input has been pharmacologically reduced. The number still has meaning for tracking change over time, but a single TyG reading under treatment is not equivalent to an unmedicated TyG reading. Corticosteroids raise both inputs and can inflate the index beyond baseline.

No — TyG is a surrogate, not a substitute. If you can get fasting insulin on your lab panel, do that. The HOMA-IR Calculator (which uses fasting insulin and glucose) is more precise. Use TyG when fasting insulin is not on a standard panel, when retroactively analyzing older lab results that did not include insulin, or to triangulate a HOMA-IR result with a second data point from the Fasting Insulin Interpreter.

TyG responds to the same interventions that improve insulin sensitivity broadly: reducing refined-carbohydrate intake, regular movement (resistance training plus Zone 2 cardio), consistent sleep, and managing chronic stress. Lifestyle interventions typically move TyG meaningfully in 8 to 12 weeks. Both inputs — triglycerides and glucose — track with these changes, so the index moves when the underlying metabolic load eases. Pair TyG tracking with the HbA1c Interpreter for a longer-window view and the Lipid Panel & Ratios for the downstream picture.