HOMA-IR insulin resistance calculator

Enter glucose in either mg/dL or mmol/L and insulin in µIU/mL, and the calculator applies the matching HOMA1-IR equation. The computation runs entirely offline, uses no randomness, and reports the formula alongside the result. HOMA-IR is an estimate for discussion with a qualified clinician, not a diagnosis or a substitute for medical evaluation.

Prepare the two fasting measurements

Use fasting plasma glucose and fasting insulin collected from the same blood draw after the fasting period specified by the clinician or laboratory. Do not combine a glucose result from one date with an insulin result from another, because HOMA-IR is intended to describe their relationship under the same fasting conditions. Enter glucose as a positive finite number and choose the unit printed on the report: mg/dL or mmol/L. Enter fasting insulin in µIU/mL; this is numerically equivalent to mIU/L. Check decimal separators and units carefully before calculating. A glucose value entered as 95 mg/dL is reasonable input syntax, while entering that same number as 95 mmol/L changes the calculation dramatically. The calculator rejects missing values, zero, negative values, unsupported units, and numbers that cannot produce a finite result. It does not verify whether a laboratory value is physiologically plausible, whether fasting was adequate, or whether medication, acute illness, pregnancy, assay differences, or another clinical factor affects interpretation. Those questions require clinical context beyond two numeric fields.

Understand how the index is calculated

HOMA-IR is a dimensionless estimate derived from fasting insulin and fasting glucose. When glucose is supplied in mg/dL, the calculator multiplies fasting insulin by fasting glucose and divides by 405. When glucose is supplied in mmol/L, it divides the same product by 22.5. These are corresponding forms of the HOMA1-IR equation, with the different divisors accounting for the glucose unit. The displayed result is rounded to three decimal places for a stable, readable response, while the calculation uses the supplied numeric values before rounding. The response also echoes both measurements, their units, and the exact formula selected, making unit mistakes easier to detect in an automated workflow. Because the operation is pure arithmetic, identical input always gives identical output. There are no network calls, stored profiles, random values, or time-dependent fields. This calculator implements HOMA1-IR rather than a proprietary HOMA2 model, and it does not attempt to reproduce specialized software that may account for nonlinear physiology or distinguish insulin assay variants.

Interpret the result with appropriate caution

A higher HOMA-IR value generally reflects a higher estimated degree of insulin resistance, but there is no single universal cutoff that is appropriate for every person, laboratory, research cohort, or clinical purpose. Published thresholds vary with age, population, metabolic status, assay method, and the question being studied. For that reason, the calculator returns the numeric index without labeling it normal, borderline, or diagnostic. Compare the result only with a reference or decision rule selected by a qualified clinician or by the protocol governing your study. A HOMA-IR result should be considered alongside symptoms, medical history, repeat measurements, laboratory reference information, and other relevant tests. It cannot confirm or exclude diabetes, prediabetes, metabolic syndrome, or another condition on its own. If an input or result seems unexpected, first confirm that both samples were fasting, the measurements came from the same draw, and the glucose unit was selected correctly. Seek professional medical advice for interpretation or decisions about treatment. The offline browser calculation is useful for private one-off checks, while the API costs $0.002 per request when the same deterministic calculation needs to be automated.