HOMA-IR Calculator

Estimates insulin resistance from fasting plasma glucose and fasting serum insulin using the Homeostasis Model Assessment (HOMA) equation.

Endocrinology EndocrinologyEvidence-BasedUpdated 2026-08-06

Clinical Notes

Formula

HOMA-IR = (glucose * insulin) / 405

Normal Range

< 2.5

Clinical Notes

Interpret results together with the patient's clinical presentation.

References

MedCalcHub Clinical References

Calculator Information

Specialty

Endocrinology

📋 Reference Ranges

Normal Range

< 2.5

Reference ranges for this calculator
Classification	Range
Normal insulin sensitivity	<2.6
Mild insulin resistance	2.5–5
Severe insulin resistance	≥5

What This Calculator Measures

Calculates the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) to estimate insulin resistance from fasting glucose and insulin levels.

How to Use

Obtain fasting serum glucose (mg/dL) and fasting insulin (µU/mL).
Enter both values into the calculator.
Review the HOMA-IR value and interpretation.

Interpretation Guide

HOMA-IR ≤2.5 is generally considered normal. Values >2.5 suggest increasing insulin resistance. Higher values indicate greater insulin resistance and metabolic risk.

Clinical Significance

HOMA-IR provides a simple, inexpensive estimate of insulin resistance that is useful in identifying patients at risk for type 2 diabetes and cardiovascular disease, and in monitoring the effectiveness of lifestyle interventions.

When to Use

Research settings assessing insulin resistance
Clinical evaluation of metabolic syndrome
Monitoring response to lifestyle interventions for insulin resistance
Complementing HOMA-B to distinguish insulin resistance from beta-cell dysfunction

When Not to Use

In type 1 diabetes (beta-cell destruction makes HOMA-IR unreliable)
In patients on exogenous insulin (exogenous insulin affects the calculation)
As a standalone diagnostic test for insulin resistance

Limitations

Requires fasting samples; non-fasting values are unreliable.
Less validated in certain ethnic populations and age groups.
Does not replace dynamic tests such as the hyperinsulinemic-euglycemic clamp.
Insulin assay variability between laboratories can affect results.

Worked Example

A 45-year-old woman with a family history of type 2 diabetes has a fasting glucose of 110 mg/dL and fasting insulin of 15 µU/mL.

Inputs:

glucose: 110

insulin: 15

HOMA-IR = (110 × 15) / (405) ≈ 4.07. This is above the normal threshold and indicates insulin resistance; evaluation for metabolic syndrome is warranted.

Evidence

Source: Endocrinology / Diabetes
Reference: Matthews DR, Hosker JP, Rudenski AS, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28:412-419.
Reviewed By: MedCalcHub Clinical Team
Version: 1.0
Updated: 2026-08

Matthews DR, et al. Diabetologia. 1985;28:412-419.

References

Matthews DR, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28:412-419. (Original Description)

Frequently Asked Questions

What does a high HOMA-IR mean?

A HOMA-IR > 2.5 suggests insulin resistance, meaning the body's cells are not responding efficiently to insulin. This is a risk factor for type 2 diabetes, metabolic syndrome, and cardiovascular disease.

What are the units of HOMA-IR?

HOMA-IR is unitless. It is calculated using fasting glucose in mg/dL and fasting insulin in µU/mL: (glucose × insulin) / 405.

How does HOMA-IR differ from HOMA-B?

HOMA-IR estimates insulin resistance, while HOMA-B estimates pancreatic beta-cell function. Both use the same fasting glucose and insulin values but different formulas.

When should HOMA-IR be measured?

HOMA-IR requires fasting for at least 8 hours. It is best measured in the morning before any food intake.

Disclaimer: This calculator is intended for educational and research purposes only. HOMA-IR is a research and screening tool and should not be used as a standalone diagnostic test. Clinical decisions should be based on comprehensive metabolic assessment.