HOMA-IR — insulin resistance calculator

What HOMA-IR estimates

The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) is a calculation derived from a single fasting blood sample that estimates how much insulin your body needs to keep blood glucose stable. Matthews and colleagues introduced it in 1985 (Diabetologia 1985;28:412–419) as a research tool; it is now widely used in metabolic medicine, endocrinology, and PCOS / NAFLD work-ups as a low-cost screening proxy for insulin resistance.

HOMA-IR is screening, not diagnostic. ADA does not endorse it as a primary clinical decision tool, partly because cut-offs vary by population and partly because more direct tests (HbA1c, OGTT) exist for prediabetes and diabetes. Where HOMA-IR is most useful: tracking metabolic trend before glucose becomes elevated, providing context in PCOS or fatty liver evaluations, and screening high-risk family members.

The formula

HOMA-IR = (fasting glucose × fasting insulin) / 22.5 (glucose in mmol/L, insulin in μIU/mL)

HOMA-IR = (fasting glucose × fasting insulin) / 405 (glucose in mg/dL, insulin in μIU/mL)

Both forms give the same number. The calculator accepts either unit and converts automatically.

Bands (Polish / European-leaning thresholds)

Polish endocrinology and many European labs use 2.5 as the resistance threshold; some US labs use 2.6–3.0. Asian populations tend to have lower thresholds (often 1.8–2.0). The trend over time is more reliable than any single number.

How to interpret a result

• Single sample variability is 15–25 % between draws. Confirm with a repeat sample 2–4 weeks apart if you can.
• Acute illness, intense exercise the day before, alcohol, or significant stress can all shift HOMA-IR transiently. Try to test under typical conditions.
• Insulin must be measured in the same blood draw as glucose for the calculation to be valid. A mismatched sample is uninterpretable.
• HOMA-IR is only meaningful in the early-to-mid stages of metabolic dysfunction. In advanced type 2 diabetes the pancreas can no longer produce enough insulin, so HOMA-IR underestimates the true resistance.

What raises HOMA-IR

• Excess body fat, especially abdominal (visceral) fat
• Sedentary lifestyle, prolonged sitting
• Sleep deprivation or poor sleep quality
• Chronic stress, elevated cortisol
• Polycystic ovary syndrome (PCOS)
• Non-alcoholic fatty liver disease (NAFLD)
• Family history of type 2 diabetes
• Some medications (corticosteroids, certain antipsychotics, some HIV medications)

What lowers HOMA-IR

• 150–300 minutes per week of moderate aerobic exercise
• 2–3 strength training sessions per week
• 5–7% weight loss if overweight (often reduces HOMA-IR by 30–50%)
• 7–9 hours of regular sleep
• Diet patterns emphasising fibre (vegetables, legumes, whole grains) and protein over refined carbohydrates
• Time-restricted eating in some studies (modest effect)

Why early action matters

Insulin resistance often precedes type 2 diabetes by 5–10 years. The Diabetes Prevention Program (Knowler 2002) showed that structured lifestyle change reduces incident type 2 diabetes by 58% over 3 years in adults with prediabetes. Reversal is most achievable in the borderline and early resistance bands; once beta-cell function declines, restoring full insulin sensitivity becomes harder.

Pair with our other tools

• Glucose unit converter & ADA interpretation — fasting glucose, OGTT, HbA1c interpretation.
• BMI calculator — weight category screening.

Privacy

All calculations run in your browser. We never see, log, or store your glucose or insulin values. Only an anonymous event (locale, band) is sent to a privacy-respecting analytics service.

Licence

The HOMA-IR formula is in the public domain. The original publication: Matthews D. R. et al., “Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man,” Diabetologia 1985;28:412–419.