CDC · Adult BMI calculator (opens in a new tab)
Adult BMI screening context and age scope.
Follow the method to its source.
Original research and official guidance behind the equations. External references open in a new tab.
NICE NG246 · Measuring waist-to-height ratio (opens in a new tab)
Waist measurement technique and central-adiposity assessment.
MedlinePlus · Insulin in blood test (opens in a new tab)
Purpose, preparation and factors affecting an insulin assay.
MedlinePlus · Fasting for a blood test (opens in a new tab)
General preparation guidance; follow the ordering clinician’s instructions.
Oxford HOMA calculator and FAQs (opens in a new tab)
Official model guidance, HOMA1 equations, assay limitations and HOMA2 software.
Matthews et al. · HOMA, 1985 (opens in a new tab)
Original fasting glucose–insulin model.
Wallace et al. · Use and abuse of HOMA, 2004 (opens in a new tab)
Practical interpretation and limitations of homeostasis modelling.
Katz et al. · QUICKI, 2000 (opens in a new tab)
Original quantitative insulin sensitivity check index.
Zhou et al. · TyG methodology, 2024 (opens in a new tab)
Explicit ln[TG × glucose / 2] convention used by this calculator.
Nathan et al. · ADAG study, 2008 (opens in a new tab)
Relationship between HbA1c and estimated average glucose.
NGSP · IFCC standardization of HbA1c (opens in a new tab)
Master equation relating NGSP percent to IFCC mmol/mol.
Mayo Clinic Laboratories · C-peptide (opens in a new tab)
C-peptide conversion and the insulin factor 6.945 used here.
NIDDK · Insulin resistance and prediabetes (opens in a new tab)
Patient information on insulin resistance, risk factors and assessment.
NIDDK · Diabetes tests and diagnosis (opens in a new tab)
Diagnostic blood tests and fasting preparation.
NIDDK · The A1C test and diabetes (opens in a new tab)
What A1C measures and circumstances that affect accuracy.
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EndoCalc. HOMA-IR calculator. https://homacalculator.com/calculators/homa-ir-calculator/ Accessed 22 October 2026.