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.
• Waist-to-hip ratio calculator — abdominal obesity screening, often a stronger predictor than BMI.

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.