estimatea1c.com / About
estimatea1c.com is a free reference for translating between A1C, average glucose, and time in range, built and maintained by the team behind SteadyRange, a private glucose and weight tracking app.
Lab reports, glucose meters, and CGMs all describe the same blood sugar in different units and on different clocks. A lab says 6.5%; a meter says 140 mg/dL; a UK clinic says 48 mmol/mol. This site exists to move between those numbers instantly, and to explain, in plain language, what they mean and what the evidence says about changing them.
Every conversion on this site uses published, citable formulas: the ADAG study equation for estimated average glucose (Nathan et al., Diabetes Care, 2008), the Bergenstal et al. equation for GMI (2018), and the IFCC master equation for mmol/mol. Clinical ranges and targets follow the American Diabetes Association's Standards of Care. When a page cites a trial (DPP, DiRECT, UKPDS, DCCT), the claim is drawn from the published results, and we say so on the page.
It is not medical advice, and it does not replace a laboratory test or a clinician. Estimates built from population-average formulas can differ from your real values, and every page says so. Nothing here should change what medication you take.
Questions and corrections are welcome via the SteadyRange contact page.
SteadyRange logs your glucose and weight, shows time in range and estimated A1C as they move, and exports a clean PDF for your next appointment. Private by default.
Try SteadyRange →Medical disclaimer. This page is general education, not medical advice, and uses population-average formulas (ADAG) to estimate average glucose. Individual factors — anemia, pregnancy, kidney disease, hemoglobin variants — can shift real values. Do not start, stop, or change any medication based on this page. Always consult a qualified healthcare provider about your results, targets, and treatment.