HOMA-IR calculator
Estimate fasting insulin resistance using the original HOMA1 equations. Check your units, review the method, and keep the result in clinical context.
Formula & units
HOMA1-IR = glucose (mg/dL) × insulin (µIU/mL) ÷ 405
For glucose in mmol/L, divide glucose × insulin by 22.5. HOMA1-%B = 360 × insulin ÷ (glucose in mg/dL − 63). Reciprocal sensitivity = 100 ÷ HOMA1-IR; it is an algebraic index, not a measured percentage of insulin response.
Worked example
Glucose 90 mg/dL and insulin 10 µIU/mL give HOMA1-IR 2.22, HOMA1-%B 133.3%, and reciprocal sensitivity 45.0%.
What the result can tell you
HOMA1-%B is undefined at glucose ≤63 mg/dL (3.5 mmol/L) and unstable near that boundary. It does not measure the percentage of surviving beta cells. There is no universal diagnostic HOMA-IR cutoff.
Read the interpretation guide →
Sources for this method
Questions about HOMA-IR
What does HOMA-IR measure?
HOMA-IR estimates fasting insulin resistance from glucose and insulin. It is a surrogate index derived from a model, rather than a direct measurement of tissue glucose uptake.
Source: Matthews et al. · HOMA, 1985 (opens in a new tab) · Related calculator → · Link to answer
How is HOMA-IR calculated?
Multiply fasting glucose in mg/dL by fasting insulin in µIU/mL and divide by 405. With glucose in mmol/L, divide the product by 22.5.
Source: Matthews et al. · HOMA, 1985 (opens in a new tab) · Related calculator → · Link to answer
What is a normal HOMA-IR level?
There is no universal normal cutoff. Assays and study populations differ; use an appropriate laboratory or research reference with clinical interpretation.
Source: Oxford HOMA calculator and FAQs (opens in a new tab) · Related calculator → · Link to answer
What is the difference between HOMA1 and HOMA2?
HOMA1 uses simple approximation equations. HOMA2 uses an iterative computer model; its results cannot be reproduced by relabelling the HOMA1 equations.
Source: Oxford HOMA calculator and FAQs (opens in a new tab) · Related calculator → · Link to answer
Does this website calculate HOMA2-IR?
No. EndoCalc calculates HOMA1. For HOMA2, use Oxford’s official software and follow its licensing and input requirements.
Source: Oxford HOMA calculator and FAQs (opens in a new tab) · Related calculator → · Link to answer
Does HOMA-%B show how many beta cells I have left?
No. HOMA-%B estimates basal beta-cell function relative to a reference. It does not count cells or directly measure beta-cell mass.
Source: Wallace et al. · Use and abuse of HOMA, 2004 (opens in a new tab) · Related calculator → · Link to answer
Related reading
HOMA-IR normal range: why cutoffs differ
A reference range only helps when it matches the model, assay and population used for your result.
Read the guide →LEARNING GUIDEFasting insulin vs HbA1c: what each test tells you
These markers describe different aspects of glucose regulation. One cannot be converted into the other.
Read the guide →LEARNING GUIDEFasting glucose and insulin test preparation
Start with the instructions for the tests actually ordered. A calculator cannot repair an unsuitable sample.
Read the guide →Related calculators
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