HOMA-IR Calculator

Enter your fasting glucose and fasting insulin from the same blood draw to get your HOMA-IR insulin resistance score. It runs in your browser and sends nothing anywhere.

HOMA-IR = fasting glucose (mg/dL) × fasting insulin (µIU/mL) ÷ 405. With glucose in mmol/L, divide by 22.5 instead. A higher score means your body needs more insulin to hold glucose steady. No guideline sets one cut-off; FixFirst's analyzer treats 1.8 or below as optimal and 3.0 or above as high.

Matthews 1985 formula US and SI units Nothing leaves your browser
Glucose unit
Insulin unit
Enter both fasting values to see your score. Everything is computed locally in your browser.

What your HOMA-IR score means

No clinical guideline publishes a HOMA-IR cut-off, and studies set theirs by population, age and assay. The bands below are the ones FixFirst's analyzer applies when it reads a lab report, so this calculator and your full report agree.

BandHOMA-IRWhat it suggests
Optimal1.8 or belowA normal amount of insulin keeps fasting glucose in range.
BorderlineAbove 1.8 to 2.9Your pancreas is putting out more insulin to hold glucose steady. This often shows up years before glucose or HbA1c rise.
High3.0 to 5.0A pattern consistent with insulin resistance. Worth raising with your doctor alongside HbA1c.
Very highAbove 5.0Marked insulin resistance. Book an appointment and ask for HbA1c if you haven't had one recently.
HOMA-IR does not diagnose diabetes
The American Diabetes Association diagnoses prediabetes and diabetes from fasting glucose, HbA1c or an oral glucose tolerance test. HOMA-IR is a research measure. Its use is catching insulin resistance while those three still look normal. It isn't valid if you inject insulin, because the measured insulin is then partly your dose.

Worked example: glucose 95, insulin 12

Both values are inside most labs' printed reference ranges, and the report would carry no flag.

US units
HOMA-IR = glucose mg/dL × insulin µIU/mL ÷ 405
95 × 12 ÷ 405 = 2.81
SI units
HOMA-IR = glucose mmol/L × insulin µIU/mL ÷ 22.5
5.3 × 12 ÷ 22.5 = 2.83

2.81 lands in the borderline band. Neither number is flagged on its own. Multiplied together, they show a pancreas working harder than usual to hold a normal glucose.

The two constants do the same job. 405 is 22.5 × 18, the mg/dL-to-mmol/L factor for glucose rounded to 18, so both versions give the same answer within rounding. For insulin reported in pmol/L, the calculator divides by 6.945 first.

Getting a HOMA-IR you can trust

Take both tests from one draw after an overnight fast. The American Diabetes Association defines fasting as no calories for at least 8 hours. Glucose and insulin drawn on different days can't be combined.

Insulin assays differ between labs more than glucose assays do. Compare HOMA-IR over time from the same lab, and read a trend of two or three results over a single number.

The two changes with the most direct effect on insulin sensitivity are resistance training, which builds muscle that clears glucose, and cutting refined carbohydrate. Short sleep and missed training days push the score back up. A retest after about three months of consistent change shows whether it's working. Our fasting insulin guide covers when to order the test and what to ask your doctor.

En español: calculadora del índice HOMA-IR, con la misma fórmula en mg/dL o mmol/L.

Frequently asked questions

How is HOMA-IR calculated?
HOMA-IR = fasting glucose (mg/dL) × fasting insulin (µIU/mL) ÷ 405. In SI units, use fasting glucose in mmol/L and divide by 22.5 instead. Both values must come from the same overnight-fasted blood draw. The formula comes from Matthews et al., Diabetologia, 1985.
What is a normal HOMA-IR?
No clinical guideline sets a single HOMA-IR cut-off, and published studies disagree by population, age, and assay. FixFirst's analyzer treats 1.8 or below as optimal, above 1.8 as borderline, 3.0 and above as high, and above 5.0 as very high. HOMA-IR is a research measure, not a diagnostic test: diabetes and prediabetes are diagnosed from fasting glucose, HbA1c, or a glucose tolerance test.
How do I convert insulin from pmol/L to µIU/mL?
Divide pmol/L by 6.945, the factor this calculator uses. Some labs calibrate to an older insulin reference and use 6.0 instead, a gap of about 14%. If your lab prints its own factor, trust it over ours.
Is HOMA-IR the same as HOMA2-IR?
No. HOMA2 is the updated computer model from Levy, Matthews and Hermans (Diabetes Care, 1998). It uses a program rather than a single division, and its numbers do not line up with the original formula's. If your report says HOMA2-IR, compare it only with other HOMA2 results.
Note: This calculator is for information and does not replace medical advice. It uses the original 1985 HOMA formula, not HOMA2, and is not valid for people using insulin therapy.

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