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How to Calculate HOMA-IR (Insulin Resistance)

Learn how to calculate HOMA-IR from fasting glucose and insulin values, what the result means, and how it compares to the QUICKI formula.

Updated 2026-07-03

Free calculators used in this guide

HOMA-IR CalculatorQUICKI CalculatorBlood Sugar Converter

Overview

HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) estimates how well your body responds to insulin using two values from a single fasting blood draw. This article walks through the calculation and how to interpret the result.

This is an educational explanation, not medical advice — a high or low HOMA-IR score should be discussed with a healthcare provider rather than self-interpreted as a diagnosis.

What You Need

  • Fasting glucose, from a blood test taken after an 8–12 hour fast
  • Fasting insulin, from the same blood draw
  • Glucose measured in mmol/L and insulin in µIU/mL (the units the standard formula expects)

Steps

  1. Get both values from the same fasting blood draw. Fasting glucose alone or fasting insulin alone isn't enough — HOMA-IR needs both from the same sample, since they're evaluated together.

  2. Check your units. If your glucose result is in mg/dL (common in the US) rather than mmol/L, convert it first using the Blood Sugar Converter.

  3. Multiply glucose (mmol/L) by insulin (µIU/mL). This is the numerator of the HOMA-IR formula.

  4. Divide the result by 22.5. This constant normalises the score so that a HOMA-IR of 1.0 represents a reference level of normal insulin sensitivity.

  5. Use the HOMA-IR Calculator to skip manual conversion and arithmetic. The HOMA-IR Calculator takes your fasting glucose and insulin values directly and returns the calculated score.

  6. Cross-check with QUICKI for a second perspective. The QUICKI Calculator uses the same two values with a different formula, giving an independent estimate from the same blood draw.

Common Mistakes to Avoid

  • Using non-fasting values — even a small amount of recent food intake can significantly skew both glucose and insulin, invalidating the result.
  • Mixing up units — using mg/dL glucose without converting to mmol/L first will produce a HOMA-IR value roughly 18 times too high.
  • Treating a single elevated score as a diagnosis — HOMA-IR is a research and screening tool; diagnosis of insulin resistance or diabetes requires clinical evaluation and often repeated testing.

Formula & Methodology

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, though your doctor's interpretation should always account for your full clinical picture.

For a fuller definition, see our glossary entry on HOMA-IR.

Frequently Asked Questions

You need fasting blood glucose and fasting insulin, both drawn from the same blood sample after an overnight fast (typically 8–12 hours) — using non-fasting values will produce an inaccurate result. The [HOMA-IR Calculator](/homa-ir-calculator/) requires exactly these two values.
A HOMA-IR 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. Values notably above this range suggest insulin resistance and warrant discussion with a doctor.
The standard HOMA-IR 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 to be converted first. The [Blood Sugar Converter](/blood-sugar-converter/) handles that conversion before you calculate HOMA-IR.
Both use the same two fasting values (glucose and insulin), but QUICKI applies a logarithmic transformation to the formula, which some research suggests correlates more consistently with directly measured insulin sensitivity than HOMA-IR. Calculating both with the [QUICKI Calculator](/quicki-calculator/) and [HOMA-IR Calculator](/homa-ir-calculator/) from the same blood draw gives two independent perspectives.
No — HOMA-IR requires a fasting insulin value, which isn't something home glucose meters measure, so you need an actual lab blood draw that tests both fasting glucose and fasting insulin together. A home meter alone can't provide the insulin half of the equation.
Most labs require 8–12 hours of fasting (water is fine) before drawing blood for fasting glucose and insulin, since even a small amount of recent food intake can meaningfully raise both values. Follow your specific lab's instructions, as fasting requirements can vary slightly.
Yes — insulin resistance often develops years before blood glucose itself becomes abnormal, so HOMA-IR can flag an elevated risk profile in people who feel completely fine and have normal standard glucose readings. This is why it's sometimes used as an early screening tool alongside other risk factors.
Conditions like polycystic ovary syndrome (PCOS), obesity, and certain medications can also elevate HOMA-IR independent of diabetes risk specifically, since insulin resistance is a broader metabolic marker, not exclusively a diabetes indicator. Discuss any elevated result with a doctor who can consider your full medical picture.
Weight loss, regular exercise, and dietary changes (particularly reducing refined carbohydrates) are commonly associated with improved insulin sensitivity and lower HOMA-IR scores in follow-up testing, though individual results vary. Retesting after a few months of sustained lifestyle changes is a common way to track progress.
HOMA2-IR is a more refined computer-modelled version of the original formula that accounts for variations in hepatic and peripheral insulin resistance more precisely, but it requires specialised software rather than a simple manual calculation. The basic HOMA-IR formula covered here remains widely used for general screening purposes.

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