M+QuickMedCalc
Educational reference only. Not a diagnostic tool. See full disclaimer.
EndocrinologyHOMA-IR

HOMA-IR Calculator (HOMA1)

Calculate the original HOMA1-IR index from paired fasting insulin and glucose, with glucose-unit normalization, assay limitations and no universal diagnostic cutoff.

Content updated: View sources

QuickMedCalc is developed and maintained by an independent developer. Medical content is not independently reviewed by a physician.

Formula and medical content are based on the references listed on this page. See sources, About, and Sources and Review Process.

Use fasting insulin and glucose obtained together from the same fasting assessment. This historical HOMA1 calculation is intended to reflect endogenous fasting insulin–glucose homeostasis; if exogenous insulin therapy may affect the measured insulin, do not interpret the result as an endogenous HOMA-IR estimate. This calculator cannot verify fasting status, specimen pairing, collection timing, or treatment context.

Select the insulin unit printed on the report.

µU/mL

Enter the fasting insulin value reported in µU/mL or mIU/L; these units are numerically equivalent. This page does not convert insulin from pmol/L.

Select the glucose unit printed on the paired laboratory report.

mg/dL

Enter the fasting glucose value from the paired sample and select the unit printed on the report.

HOMA-IR result will appear here

Enter insulin and glucose from the same fasting assessment. This calculator reports the HOMA1-IR arithmetic without assigning a normal, abnormal, or insulin-resistance category.

About

HOMA-IR is a fasting surrogate index derived from insulin and glucose. This calculator reproduces the original linear HOMA1-IR formula from paired fasting values. It does not run Oxford HOMA2 and does not diagnose insulin resistance, prediabetes, or diabetes. [1, 4]

Formula

HOMA1-IR = fasting insulin (µU/mL) × fasting glucose (mg/dL) ÷ 405.
HOMA1-IR = fasting insulin (µU/mL) × fasting glucose (mmol/L) ÷ 22.5.
Glucose (mmol/L) = glucose (mg/dL) ÷ 18.
µU/mL and mIU/L are numerically equivalent for insulin reporting.

Interpretation

What is HOMA-IR?

Homeostasis Model Assessment relates fasting steady-state glucose and insulin. This page calculates only the original linear HOMA1-IR surrogate; it is not a direct measurement of insulin sensitivity. Different glucose and insulin combinations can produce the same index. [1, 2]

Is there a normal HOMA-IR range?

No universal threshold exists. Oxford states that HOMA indices have no absolute value and defines no normal-versus-abnormal thresholds because values depend on the glucose, insulin, and C-peptide assays used. Population, age, BMI, glycemic state, and study endpoint add further context, so this page applies no result category. [3, 7]

A population-specific reference example

In a 2021 German population cohort using a specific insulin immunoassay and a stringently selected reference group, the 97.5th percentile was 2.35. The same study found systematic differences between insulin assays. That number describes one study and assay context; it is not a QuickMedCalc normal range or a cutoff applied to the result. [7]

HOMA-IR formula and worked example

With glucose in mg/dL, HOMA1-IR is fasting insulin × fasting glucose ÷ 405. With glucose in mmol/L, the equivalent expression is fasting insulin × fasting glucose ÷ 22.5. For paired fasting insulin 10 µU/mL and glucose 90 mg/dL, this calculator returns 2.22. This example is generated by the same runtime used by the form and assigns no category. [1]

HOMA1 vs HOMA2

HOMA1 is the historically widely used linear approximation. HOMA2 is Oxford’s updated nonlinear computer model, accounting for additional nonlinear physiology and using an iterative implementation. Oxford distributes the HOMA2 Calculator and API under its licensing terms. This page calculates HOMA1 only; it does not copy, reverse-engineer, derive, or label a HOMA1 result as HOMA2, HOMA-%B, or HOMA-%S. [2, 3, 4]

Oxford’s current HOMA history says the widely used HOMA1 linear equations are not appropriate for currently available insulin assays and points to the recalibrated HOMA2 model for contemporary assay-based HOMA modeling. This is an assay and model boundary, not a claim that the historical HOMA1 equation is mathematically invalid or can never be used in research. [4]

Can HOMA-IR diagnose insulin resistance?

No universal clinical diagnostic threshold has been established. HOMA is a fasting surrogate used widely in research and epidemiology. The hyperinsulinemic-euglycemic clamp is a reference method for direct assessment, but that does not make a clamp a routine requirement for every person. This calculator does not diagnose insulin resistance. [3, 5, 6]

HOMA-IR, HbA1c, and diabetes testing

HOMA1-IR is a fasting insulin-and-glucose-derived surrogate; HbA1c reflects longer-term glycemic exposure. They are different quantities and cannot be converted into one another. ADA 2026 diagnoses diabetes using accepted A1C or plasma-glucose criteria: fasting plasma glucose, 2-hour plasma glucose during an OGTT, or random plasma glucose in the appropriate symptomatic or hyperglycemic-crisis context. HOMA-IR is not one of those diagnostic criteria. [8]

Assay and fasting-sample limitations

Use fasting insulin and glucose collected together in one basal assessment. Insulin assays are not sufficiently standardized for universal transfer of derived thresholds. The 2023 ADA/AACC laboratory guideline says routine insulin or proinsulin testing is not recommended for most people with diabetes or at risk for diabetes or cardiovascular disease and that these assays are useful primarily for research. HOMA is intended to reflect endogenous fasting insulin–glucose homeostasis; if exogenous insulin affects the measured insulin, endogenous HOMA interpretation may be inappropriate. This calculator cannot determine whether that treatment context applies. [2, 6]

µU/mL and mIU/L are numerically equivalent in this implementation. Insulin in pmol/L is not supported because activity-to-mass conversion and assay standardization require method-specific care. A real unit change clears the corresponding value rather than silently reinterpreting it.

Clinical boundaries

Acute illness, physiologic stress, recent food, pregnancy, childhood, severe beta-cell failure, marked hypo- or hyperglycemia, medicines, kidney or liver disease, and assay interference can change interpretation. This page does not diagnose prediabetes, diabetes, PCOS, metabolic syndrome, or another condition; infer A1C or OGTT results; or recommend diet, exercise, weight loss, medication, supplements, testing, or treatment. [2, 6, 8]

References

  1. 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(7):412–419. PMID 3899825. DOI 10.1007/BF00280883.
  2. Wallace TM, Levy JC, Matthews DR. Use and abuse of HOMA modeling. Diabetes Care. 2004;27(6):1487–1495. PMID 15161807. DOI 10.2337/diacare.27.6.1487.
  3. University of Oxford Diabetes Trials Unit. HOMA Calculator — Frequently Asked Questions. Current HOMA2 implementation, licensing, input, and no-defined-threshold guidance. Accessed September 4, 2026.
  4. University of Oxford Diabetes Trials Unit. HOMA Calculator — History. HOMA1 linear equations, current-assay limitation, HOMA2 recalibration, and licensed distribution history. Accessed September 4, 2026.
  5. Muniyappa R, Lee S, Chen H, Quon MJ. Current approaches for assessing insulin sensitivity and resistance in vivo: advantages, limitations, and appropriate usage. Am J Physiol Endocrinol Metab. 2008;294(1):E15–E26. PMID 17957034. DOI 10.1152/ajpendo.00645.2007.
  6. Sacks DB, et al. Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus. Diabetes Care. 2023;46(10):e151–e199. PMID 37471273. PMCID PMC10516260. DOI 10.2337/dci23-0036.
  7. Matli B, et al. Distribution of HOMA-IR in a population-based cohort and proposal for reference intervals. Clin Chem Lab Med. 2021;59(11):1844–1851. PMID 34380182. DOI 10.1515/cclm-2021-0643.
  8. American Diabetes Association Professional Practice Committee for Diabetes. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S27–S49. DOI 10.2337/dc26-S002.

FAQ

Related Calculators

HbA1c

Convert HbA1c/A1C between NGSP percent and IFCC mmol/mol, calculate eAG in mg/dL or mmol/L, or express representative eAG as an ADAG-equivalent estimated A1C.

TSH

Analyze stable nonpregnant adult TSH and Free T4, with optional Free T3, against the reporting laboratory’s own intervals and show the resulting descriptive biochemical pattern.

Anthropometry

Calculate adult BMI for men and women with the same formula and BSA with Mosteller, Du Bois, or Haycock from height and weight; add optional measurements for other named anthropometry models.

Disclaimer

Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.