HOMA-IR Calculator for Insulin Resistance Calculator

HOMA-IR Calculator for Insulin Resistance Calculator for Endocrinology. Higher values indicate a higher modeled fasting resistance estimate under the assumptions of HOMA1. They do not identify the cause or establish that medication is needed. A study-specific cutoff cannot automatically become a diagnostic threshold in another population.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

HOMA1-IR = fasting glucose in mmol/L x fasting insulin in micro-units/mL / 22.5. Glucose entered in mg/dL is divided by 18.0182 first. This simple fasting approximation is not the computerized HOMA2 model; the output is a continuous index without diagnostic bands.

When to use this calculator

Use for teaching fasting insulin-glucose relationships or in a research protocol that specifies sampling, assay and reference population. Confirm a fasting sample and the insulin units before comparing values. The index does not replace glucose-based diabetes testing.

Inputs used

  • Fasting glucose in mmol/L or mg/dL
  • Fasting insulin in micro-units/mL

Clinical interpretation

Higher values indicate a higher modeled fasting resistance estimate under the assumptions of HOMA1. They do not identify the cause or establish that medication is needed. A study-specific cutoff cannot automatically become a diagnostic threshold in another population.

Worked example

Glucose 5 mmol/L and insulin 20 micro-units/mL give 100 / 22.5 = 4.444. Glucose 4.5 with insulin 5 gives 1.000. At glucose 4.5, insulin 9.75 gives 1.950; this receives the same continuous-index explanation rather than falling into an interval gap.

Limitations and safety notes

Insulin assay differences, secretion, fasting conditions and treatment affect the result. Exogenous insulin and substantial beta-cell failure complicate interpretation. Software entry bounds are not the validated population range. No HOMA2 software, individual risk probability or treatment recommendation is supplied.

Frequently asked questions

Does a result above 2 diagnose resistance?

Not universally. The assay, population and intended outcome must support a proposed threshold; this tool deliberately does not apply one.

Can I enter insulin in pmol/L?

No. Use micro-units/mL, numerically equivalent to mIU/L. Obtain an assay-appropriate conversion from the laboratory when necessary.

References

  • Matthews et al., 1985 HOMA derivation; fasting-model purpose and precision, not a universal diagnostic threshold. https://pubmed.ncbi.nlm.nih.gov/3899825/

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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