HOMA-IR Calculator: Check Your Insulin Resistance in Seconds

Enter your fasting glucose and fasting insulin below and you get your HOMA-IR instantly: below 1.0 is optimal insulin sensitivity, 1.0–1.9 is typical, 2.0–2.9 suggests early insulin resistance, and 2.9 or above indicates significant resistance. Both values must come from the same fasting blood draw (10–12 hours, water only).

How is HOMA-IR calculated?

The formula comes from Matthews and colleagues (1985): HOMA-IR = fasting glucose (mg/dL) × fasting insulin (µIU/mL) ÷ 405. With glucose in mmol/L, divide by 22.5 instead. Worked example: glucose 95 mg/dL × insulin 8 µIU/mL = 760; 760 ÷ 405 = 1.88 — top of the typical band.

Population data broadly agree with these bands: in the Spanish EPIRCE study, HOMA-IR cut-offs associated with metabolic syndrome fell between roughly 2 and 3.9 depending on age and sex.

Why does HOMA-IR matter more than fasting glucose alone?

Because insulin moves first. In the Whitehall II cohort, people who later developed type 2 diabetes had measurably reduced insulin sensitivity more than a decade before diagnosis, while their glucose stayed deceptively normal until the final 2–3 years. An analysis of the Kraft database found that just over half of people with completely normal glucose tolerance still showed hyperinsulinaemia. Glucose is the value your body defends; insulin is the price it pays — HOMA-IR captures the price.

For the full picture — optimal fasting insulin bands, test conditions, and the evidence-backed ways to lower it — read our fasting insulin guide.

What are the limits of HOMA-IR?

Three honest caveats. It mainly reflects fasting (hepatic) insulin resistance and can miss post-meal dysfunction. It is not valid if you inject insulin. And insulin assays are not fully standardized between manufacturers, so always compute it from results drawn at the same laboratory, and judge the trend across two or three tests rather than a single number. If your result sits above 2.9 — or above 2.0 alongside an expanding waist, high triglycerides or elevated uric acid — that is a conversation to have with your doctor, not a number to panic about alone.

Tracking an intervention? Log training, sleep and diet in BioTrakk, retest after 8–12 weeks, and run it as a structured n-of-1 experiment so the verdict comes from your data rather than your hopes.