Insulin Resistance Calculator

What is insulin resistance?

Insulin resistance is the upstream metabolic lesion behind prediabetes, type-2 diabetes, fatty liver, PCOS, and a substantial component of cardiovascular risk. It happens when cells stop responding properly to insulin's signal to take up glucose — so the pancreas pumps out more insulin to compensate, and over time both the signal and the response degrade further. Petersen and Shulman's mechanism reviews¹Physiological Reviews · 2018Petersen MC, Shulman GI — Mechanisms of Insulin Action and Insulin Resistance²Journal of Clinical Investigation · 2016Samuel VT, Shulman GI — The pathogenesis of insulin resistance: integrating signaling pathways and substrate flux trace the lesion to ectopic lipid accumulation in liver and skeletal muscle — fat deposited where it doesn't belong, disrupting insulin-receptor signaling via diacylglycerol-PKCε.

How HOMA-IR works

HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) is calculated from fasting glucose × fasting insulin / 405. Wallace, Levy and Matthews' 2004³Diabetes Care · 2004Wallace TM, Levy JC, Matthews DR — Use and abuse of HOMA modeling guide is the canonical clinical reference for interpretation. Standard thresholds:

• HOMA-IR < 1.9 — insulin sensitive
• 1.9–2.9 — borderline
• ≥ 2.9 — likely insulin resistant
• ≥ 4.5 — severe insulin resistance

When you don't have labs

The proxy mode uses waist-to-height ratio (WHtR) as the primary input — Ashwell and colleagues established this as a stronger predictor of cardiometabolic risk than BMI. WHtR ≥ 0.5 is elevated; ≥ 0.6 is high visceral-fat risk. We add optional inputs (fasting glucose if you have it from a basic panel, the triglyceride-to-HDL ratio which Petersen and Shulman's work suggests as a proxy, and systolic BP) to refine the score. This is screening — not a substitute for a physician's evaluation.

If you score high

The good news: insulin resistance is reversible in most people. The Newcastle and DiRECT trials⁴Diabetologia · 2011Lim EL, Hollingsworth KG, Aribisala BS, Chen MJ, Mathers JC, Taylor R — Reversal of type 2 diabetes: normalisation of beta cell function in association with decreased pancreas and liver triacylglycerol⁵The Lancet · 2018Lean MEJ et al. — Primary care-led weight management for remission of type 2 diabetes (DiRECT): an open-label, cluster-randomised trial⁶The Lancet Diabetes & Endocrinology · 2024Taylor R et al. — Beta-cell function and remission of type 2 diabetes (5-year DiRECT extension) demonstrated type-2 diabetes remission via structured weight loss (~10–15 kg from baseline), with 46% remission at 12 months and durable response when weight loss is maintained. The lever is reducing intramyocellular and hepatic lipid — which means: a sustained energy deficit, attention to UPF and processed-carb intake, resistance training to increase muscle's glucose-disposal capacity, and adequate sleep (since circadian disruption itself worsens insulin resistance — Buxton 2012).

What this tool isn't

This is not a diagnosis. It's a screening tool to help you decide whether to talk to your physician about formal testing (fasting glucose, fasting insulin, HbA1c, an oral glucose tolerance test if indicated). HOMA-IR has well-documented limitations in obese patients, in highly trained athletes, and at the extremes of insulin secretion. Use the result to inform a conversation, not to self-diagnose.