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HOMA-IR Calculator

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Calculate HOMA-IR from fasting glucose and fasting insulin levels to estimate insulin resistance, with reference categories for interpreting your result.

Reviewed by the thecalcu.com team · Last updated July 5, 2026

Fasting Glucose
mg/dL
70300
Fasting Insulin
µIU/mL
150

Both values should come from the same fasting blood draw (at least 8 hours without food) for an accurate result.

HOMA-IR

0

Category

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For informational purposes only. Reference cutoffs vary by lab and population — discuss your result with a healthcare provider.

What is a HOMA-IR?

A HOMA-IR Calculator estimates insulin resistance using the Homeostatic Model Assessment of Insulin Resistance, a formula developed by Matthews et al. in 1985 that combines fasting glucose and fasting insulin from a single blood draw. Unlike fasting glucose alone, which can appear normal even when insulin resistance is developing, HOMA-IR reveals when the body is compensating with elevated insulin output to keep glucose in a normal range.

This calculator applies the standard formula, fasting glucose times fasting insulin, divided by 405, and maps the result to general reference categories. It pairs well with the QUICKI Calculator, which uses the same two inputs but a different mathematical transformation, and with the A1c Calculator for a longer-term view of glucose control.

Why Use a HOMA-IR Calculator?

Insulin resistance often develops gradually and silently, sometimes years before glucose levels rise enough to be flagged on routine testing. HOMA-IR offers an earlier signal by looking at how much insulin the body needs to maintain a given glucose level, making it a widely used research and screening tool for identifying insulin resistance before it progresses.

This calculator removes the need to manually apply the formula, instantly converting your fasting glucose and insulin values into a HOMA-IR score and a general interpretation category, useful context alongside the Diabetes Risk Calculator when reviewing overall metabolic risk factors.

Who Should Use This Calculator?

  • Anyone with fasting glucose and fasting insulin lab results who wants to understand what HOMA-IR they represent together.
  • People with a family history of type 2 diabetes or metabolic syndrome exploring early insulin resistance indicators.
  • Individuals with PCOS, a condition frequently associated with insulin resistance, tracking HOMA-IR alongside other markers.
  • Students and healthcare trainees studying how the HOMA-IR formula is derived and applied.
  • Anyone working with a healthcare provider on metabolic health who wants to understand their lab results better before a follow-up visit.

This calculator is for informational and educational purposes only and is not a substitute for professional medical diagnosis or treatment. Reference ranges vary by population and lab, so any HOMA-IR result should be interpreted by a qualified healthcare provider.

What Insights Does the HOMA-IR Calculator Give You?

  • HOMA-IR, the primary numeric result, calculated directly from your fasting glucose and fasting insulin values.
  • Insulin Resistance Category, a general interpretation (optimal, normal, early insulin resistance, or significant insulin resistance) based on commonly cited reference ranges, giving quick context for the numeric score.

Because HOMA-IR depends on both glucose and insulin together, the calculator makes it easy to see how a change in either value, for example, elevated fasting insulin despite normal glucose, shifts the overall score.

How to use this HOMA-IR calculator

  1. Obtain your Fasting Glucose value in mg/dL from a fasting blood test (typically after at least 8 hours without food).
  2. Obtain your Fasting Insulin value in µIU/mL from the same fasting blood draw.
  3. Enter the Fasting Glucose value into the calculator.
  4. Enter the Fasting Insulin value into the calculator.
  5. Review the HOMA-IR result and its Insulin Resistance Category, and discuss the result with a healthcare provider for personalized interpretation.
Show formula & methodology ↓Show less ↑

Formula & Methodology

HOMA-IR = (Fasting Glucose [mg/dL] × Fasting Insulin [µIU/mL]) ÷ 405

This is the original Matthews et al. formula (Diabetologia, 1985). The constant 405 applies specifically when glucose is measured in mg/dL; formulas using mmol/L glucose use a divisor of 22.5 instead.

Commonly cited reference bands: below 1.0 is optimal insulin sensitivity, 1.0-1.9 is normal, 2.0-2.9 suggests early insulin resistance, and 2.9 or above suggests significant insulin resistance.

Worked example: for a fasting glucose of 100 mg/dL and fasting insulin of 10 µIU/mL:
- HOMA-IR = (100 × 10) ÷ 405 = 2.47
- A HOMA-IR of 2.47 falls in the Early insulin resistance range (2.0-2.9).

Frequently Asked Questions

What is HOMA-IR?
HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) is a formula that estimates insulin resistance from a single fasting blood sample, using fasting glucose and fasting insulin together. It was developed by Matthews et al. in 1985 and remains one of the most widely used insulin resistance indices in both research and clinical screening.
How is HOMA-IR calculated?
HOMA-IR is calculated as fasting glucose in mg/dL multiplied by fasting insulin in µIU/mL, divided by 405. The 405 constant is specific to glucose measured in mg/dL, formulas using mmol/L glucose divide by 22.5 instead.
What is a normal HOMA-IR value?
General reference ranges suggest a HOMA-IR below 1.0 reflects optimal insulin sensitivity, roughly 1.0-1.9 is considered normal, 2.0-2.9 suggests early insulin resistance, and 2.9 or higher suggests significant insulin resistance. These cutoffs vary somewhat by population, lab assay, and study, so they should be treated as general guidance rather than fixed diagnostic thresholds.
Why do I need both fasting glucose and fasting insulin for this calculation?
Fasting glucose alone can appear normal even when the body is compensating with elevated insulin production, so HOMA-IR combines both values to reveal that compensatory pattern. A high fasting insulin alongside normal or high glucose is a classic sign of developing insulin resistance that glucose testing alone would miss.
What does a high HOMA-IR mean?
A high HOMA-IR suggests your body needs more insulin than typical to manage blood glucose, a pattern associated with increased risk of type 2 diabetes, metabolic syndrome, and cardiovascular disease over time. It does not by itself diagnose any condition and should be interpreted alongside other clinical findings.
How does HOMA-IR compare to QUICKI?
Both HOMA-IR and the [QUICKI Calculator](/quicki-calculator/) use the same two inputs, fasting glucose and fasting insulin, but QUICKI applies a logarithmic transformation that some research suggests behaves more consistently across a wider range of values. HOMA-IR moves in the opposite direction of insulin sensitivity: higher HOMA-IR means more resistance, while higher QUICKI means more sensitivity.
Do I need to fast before testing for HOMA-IR?
Yes, both the glucose and insulin measurements must come from the same fasting blood draw, typically after at least 8 hours without food, since eating raises both values and would distort the calculation. Follow your lab's specific fasting instructions for accurate results.
Can HOMA-IR diagnose insulin resistance or diabetes?
No, HOMA-IR is a research and screening index, not a standalone diagnostic test. A qualified healthcare provider should interpret your HOMA-IR result alongside your full clinical history, other lab work, and established diagnostic criteria for insulin resistance, prediabetes, or diabetes.
How does body weight affect HOMA-IR?
Higher body fat, particularly abdominal fat, is strongly associated with elevated HOMA-IR because excess fat tissue can interfere with normal insulin signaling. Tools like the [BMI Calculator](/bmi-calculator/) provide complementary context, though HOMA-IR itself is calculated independently of weight or BMI.
What lifestyle factors can improve HOMA-IR over time?
Weight management, regular physical activity, improved sleep, and dietary changes such as reducing refined carbohydrates are commonly associated with improved insulin sensitivity and lower HOMA-IR in research studies. Any lifestyle changes for managing insulin resistance should be discussed with a healthcare provider for a personalized plan.
Also known as
insulin resistance calculatorHOMA IR formulafasting insulin glucose ratioinsulin resistance indexHOMA-IR score