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HOMA-IR

General

Homeostatic Model Assessment of Insulin Resistance

A score estimating insulin resistance from fasting glucose and fasting insulin values, often flagging elevated risk years before blood glucose itself becomes abnormal.

Definition

HOMA-IR estimates how well the body responds to insulin using two values from a single fasting blood draw: fasting glucose and fasting insulin. Elevated values can signal insulin resistance years before blood glucose itself becomes abnormal on a standard test, making HOMA-IR a useful early screening indicator.

The HOMA-IR Calculator calculates this score directly from your two lab values.

Formula

HOMA-IR = (Fasting Glucose [mmol/L] × Fasting Insulin [µIU/mL]) ÷ 22.5

Worked Example

With fasting glucose of 5.5 mmol/L and fasting insulin of 8 µIU/mL:

HOMA-IR = (5.5 × 8) ÷ 22.5 = 44 ÷ 22.5 = 1.96

This falls within the commonly cited normal range.

Key Things to Know

  • Requires a true fasting blood draw: even a small amount of recent food intake can skew both glucose and insulin values.
  • Unit conversion matters: using mg/dL glucose without converting to mmol/L first produces a HOMA-IR value roughly 18 times too high.
  • Not a standalone diagnosis: a high score is a signal to discuss further testing with a doctor, not a diagnosis by itself.
  • QUICKI offers a second perspective: calculating both from the same blood draw gives two independent insulin sensitivity estimates.

Related Calculators

HOMA-IR Calculator →Calculate HOMA-IR from fasting glucose and fasting insulin levels to estimate insulin resistance, with reference categories for interpreting your result.
QUICKI Calculator →Calculate the Quantitative Insulin Sensitivity Check Index (QUICKI) from fasting glucose and insulin to estimate insulin sensitivity, with reference bands.
Diabetes Risk Calculator →Estimate your Type 2 diabetes risk score using the standard ADA-style risk test based on age, weight, activity, and family history in under a minute.

Related Terms

QUICKIQuantitative Insulin Sensitivity Check IndexGlycemic IndexGlycemic Index (GI)

Frequently Asked Questions

A score below 1.0 is often considered optimal insulin sensitivity, with values up to around 2.0–2.5 generally considered normal, though exact thresholds vary somewhat between labs and populations.
Fasting blood glucose and fasting insulin, both drawn from the same blood sample after an 8–12 hour fast. The [HOMA-IR Calculator](/homa-ir-calculator/) requires exactly these two values.
The standard formula expects glucose in mmol/L and insulin in µIU/mL — if your lab report uses mg/dL for glucose (common in the US), it needs converting first using a [Blood Sugar Converter](/blood-sugar-converter/).
Both use the same two fasting values, but [QUICKI](/glossary/quicki/) applies a logarithmic transformation, which some research suggests correlates more consistently with directly measured insulin sensitivity.
No — HOMA-IR measures insulin resistance, a risk factor and often a precursor to type 2 diabetes, but an elevated score alone doesn't mean a diabetes diagnosis, which requires specific glucose or A1C thresholds.