Calculators · Endocrinology · Conversion

Estimated average glucose from HbA1c (ADAG)

Also called eAG, HbA1c to average glucose, ADAG

Converts HbA1c (%) to estimated average glucose using the ADAG regression.

%

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Formula and scoring

eAG (mg/dL) = 28.7 × HbA1c − 46.7; eAG (mmol/L) = 1.5944 × HbA1c − 2.594.

Exam and ward pearls

  • ADAG used CGM plus fingersticks in 507 people (type 1, type 2, non-diabetic); the relation did not differ by age, sex, race or diabetes type.
  • HbA1c 6.5% ≈ 140 mg/dL; 8% ≈ 183 mg/dL.

When not to rely on it

  • Regression from 507 people with stable glycaemia in 10 centres; an individual's true mean glucose can differ from eAG.

Source

  1. Nathan DM, Kuenen J, Borg R, et al. Translating the A1C assay into estimated average glucose values. Diabetes Care. 2008;31(8):1473-8. doi:10.2337/dc08-0545 · PMID 18540046

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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