{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"a1c-to-glucose"},"result":{"entity_type":"calculator","id":"a1c-to-glucose","calculator_id":"a1c-to-glucose","canonical_url":"https://tttkmbb.com/medical/a1c-to-glucose","name":"A1C to Average Glucose Calculator","title":"A1C to Estimated Average Glucose (eAG) Calculator – ADAG Formula, Both Directions","category":"medical","category_name":"Medical & Clinical","tool_name":"convert_a1c_to_glucose","featured_mcp_tool":false,"description":"Converts HbA1c (%) to estimated average glucose in mg/dL and mmol/L with the ADAG study equation, or an average glucose back to A1C, and reports the IFCC value in mmol/mol.","use_when":"You want the average glucose implied by an A1C result, the A1C implied by an average glucose from a meter or CGM, or the NGSP-to-IFCC conversion.","do_not_use_when":"Conditions alter haemoglobin glycation (haemoglobinopathies, anaemia, recent transfusion, pregnancy, kidney failure), where A1C does not track average glucose.","inputs":[{"name":"direction","label":"Direction","type":"enum","required":false,"default":"a1c_to_glucose","values":[{"value":"a1c_to_glucose","label":"A1C (%) → average glucose","aliases":["a1c","to_glucose"]},{"value":"glucose_to_a1c","label":"Average glucose → A1C (%)","aliases":["glucose","to_a1c"]}],"description":"Which quantity is being converted.","example":"a1c_to_glucose"},{"name":"value","label":"Value","type":"number","required":true,"max":1000,"exclusive_min":0,"description":"A1C in percent (NGSP) for a1c_to_glucose, or average glucose (in glucose_unit) for glucose_to_a1c.","example":7},{"name":"glucose_unit","label":"Glucose unit","type":"enum","required":false,"default":"mg_dl","values":[{"value":"mg_dl","label":"mg/dL","aliases":["mg/dl","mgdl"]},{"value":"mmol_l","label":"mmol/L","aliases":["mmol/l","mmol"]}],"description":"Unit of the glucose value (1 mmol/L = 18.016 mg/dL).","example":"mg_dl"}],"outputs":[{"name":"a1c_percent","label":"A1C (NGSP)","type":"number","unit":"%","decimals":1,"description":"Haemoglobin A1c in NGSP/DCCT percent."},{"name":"a1c_mmol_mol","label":"A1C (IFCC)","type":"number","unit":"mmol/mol","decimals":0,"description":"IFCC units: (A1C% − 2.15) × 10.929."},{"name":"eag_mg_dl","label":"Estimated average glucose","type":"number","unit":"mg/dL","decimals":0,"description":"28.7 × A1C − 46.7."},{"name":"eag_mmol_l","label":"Estimated average glucose","type":"number","unit":"mmol/L","decimals":1,"description":"1.59 × A1C − 2.59."},{"name":"a1c_category","label":"ADA A1C category","type":"string","decimals":4,"description":"Diagnostic ranges: <5.7% normal, 5.7–6.4% prediabetes, ≥6.5% diabetes (requires confirmation)."}],"input_schema":{"type":"object","properties":{"direction":{"description":"Which quantity is being converted.","type":"string","enum":["a1c_to_glucose","glucose_to_a1c"],"default":"a1c_to_glucose","examples":["a1c_to_glucose"]},"value":{"description":"A1C in percent (NGSP) for a1c_to_glucose, or average glucose (in glucose_unit) for glucose_to_a1c.","type":"number","maximum":1000,"exclusiveMinimum":0,"examples":[7]},"glucose_unit":{"description":"Unit of the glucose value (1 mmol/L = 18.016 mg/dL).","type":"string","enum":["mg_dl","mmol_l"],"default":"mg_dl","examples":["mg_dl"]}},"additionalProperties":false,"required":["value"]},"output_schema":{"type":"object","properties":{"a1c_percent":{"description":"Haemoglobin A1c in NGSP/DCCT percent. Unit: %.","type":"number","x-unit":"%"},"a1c_mmol_mol":{"description":"IFCC units: (A1C% − 2.15) × 10.929. Unit: mmol/mol.","type":"number","x-unit":"mmol/mol"},"eag_mg_dl":{"description":"28.7 × A1C − 46.7. Unit: mg/dL.","type":"number","x-unit":"mg/dL"},"eag_mmol_l":{"description":"1.59 × A1C − 2.59. Unit: mmol/L.","type":"number","x-unit":"mmol/L"},"a1c_category":{"description":"Diagnostic ranges: <5.7% normal, 5.7–6.4% prediabetes, ≥6.5% diabetes (requires confirmation).","type":"string"}}},"formula":"eAG (mg/dL) = 28.7 × A1C − 46.7; eAG (mmol/L) = 1.59 × A1C − 2.59; inverse: A1C = (eAG_mg_dl + 46.7) / 28.7 or (eAG_mmol_l + 2.59) / 1.59; IFCC (mmol/mol) = (A1C − 2.15) × 10.929","method":"The ADAG regression (Nathan 2008) has a 95% prediction interval of roughly ±30 mg/dL at an A1C of 7%, so individual eAG values are approximate. Results are informational only and not a substitute for clinical judgement or medical advice.","sources":[{"name":"Nathan DM et al. (2008) Translating the A1C assay into estimated average glucose values, Diabetes Care 31:1473-1478","url":"https://pubmed.ncbi.nlm.nih.gov/18540046/","type":"peer_reviewed","retrieved_at":"2026-09-24"},{"name":"American Diabetes Association – Diagnosis (A1C, fasting and OGTT thresholds)","url":"https://diabetes.org/about-diabetes/diagnosis","type":"standard","retrieved_at":"2026-09-24"},{"name":"NGSP – IFCC/NGSP master equation","url":"https://ngsp.org/ifccngsp.asp","type":"standard","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"A1C 7%","inputs":{"direction":"a1c_to_glucose","value":7},"expected":{"a1c_percent":7,"eag_mg_dl":154,"eag_mmol_l":8.5,"a1c_mmol_mol":53,"a1c_category":"Diabetes range (≥6.5%)"},"url":"https://tttkmbb.com/api/v1/calculate/a1c-to-glucose?direction=a1c_to_glucose&value=7"},{"name":"Average glucose 126 mg/dL","inputs":{"direction":"glucose_to_a1c","value":126,"glucose_unit":"mg_dl"},"expected":{"a1c_percent":6,"a1c_mmol_mol":42,"a1c_category":"Prediabetes range (5.7–6.4%)"},"url":"https://tttkmbb.com/api/v1/calculate/a1c-to-glucose?direction=glucose_to_a1c&value=126&glucose_unit=mg_dl"}],"faq":[{"q":"Is eAG the same as my meter average?","a":"Roughly, if the meter average covers all times of day over about 3 months; A1C weights the most recent 4–6 weeks more heavily, and meter checks often miss post-meal peaks."},{"q":"What is the mmol/mol value?","a":"The IFCC unit used in the UK, Australia and much of Europe; 7% NGSP corresponds to 53 mmol/mol."}],"tags":["a1c","hba1c","estimated average glucose","eag","mmol/mol","diabetes"],"related":[{"calculator_id":"glucose-unit-conversion","reason":"Convert single glucose readings between units."}],"links":{"html":"https://tttkmbb.com/medical/a1c-to-glucose","markdown":"https://tttkmbb.com/medical/a1c-to-glucose.md","json":"https://tttkmbb.com/medical/a1c-to-glucose.json","api":"https://tttkmbb.com/api/v1/calculate/a1c-to-glucose","schema":"https://tttkmbb.com/api/v1/calculators/a1c-to-glucose","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:53:38Z","next_actions":[{"tool":"run_calculator","calculator_id":"a1c-to-glucose","reason":"Run A1C to Average Glucose Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/medical/a1c-to-glucose.md"}}