HOMA-IR Calculator

Assess insulin resistance from your fasting glucose and insulin levels.

Result

2.35
Early resistance

How it is calculated

HOMA-IR estimates insulin resistance from two fasting blood values: HOMA-IR = glucose × insulin / 405, where glucose is in mg/dL and insulin in µU/mL. The constant 405 applies to mg/dL; if your lab reports glucose in mmol/L, multiply by 18 first (the equivalent formula divides by 22.5). The tool then labels the result with its own bands: below 1.0 optimal, 1.0 to under 2.0 normal, 2.0 to under 2.9 early resistance, and 2.9 or more resistant. Both inputs must be above zero. Cut-offs vary between labs and populations, and this is a screening index, not a diagnosis.

Worked example

Fasting glucose 95 mg/dL and fasting insulin 10 µU/mL. Multiply: 95 × 10 = 950. Divide by 405: 950 / 405 = 2.346, shown as 2.35. That falls in the 2.0 to 2.9 band, so the tool reports Early resistance. A doctor would interpret this together with other tests.

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Common mistakes

  • Entering glucose in mmol/L into a formula built for mg/dL, which gives a value roughly 18 times too small.
  • Using a non-fasting blood sample; eating raises both glucose and insulin and inflates the index.
  • Mixing insulin units, such as pmol/L instead of µU/mL.
  • Treating the band as a diagnosis; thresholds differ between labs and populations.

Sources

About this calculator

This calculator estimates insulin resistance using the Homeostatic Model Assessment (HOMA-IR): HOMA-IR = (fasting glucose × fasting insulin) / 405 when glucose is in mg/dL (or /22.5 when glucose is in mmol/L). It approximates how well the body's cells respond to insulin from a single fasting blood draw, without the need for a clamp study.

Endocrinologists, primary care physicians, and researchers use HOMA-IR as a practical screening and research tool for insulin resistance, prediabetes, metabolic syndrome, and polycystic ovary syndrome (PCOS). HOMA-IR is a screening estimate and not a diagnosis.

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Comments (1)

  • Editorial team

    The tool expects glucose in mg/dL. If your lab reports mmol/L, multiply by 18 first: 5.0 mmol/L is about 90 mg/dL, and with insulin of 8 that gives roughly 1.78. Both values must come from the same fasting blood sample, and cut-off bands differ between labs and populations, so treat the category as orientation only. Discuss the result with your doctor. Which unit does your lab report use?

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