Skip to content
Allin
Sign up · Sign in

HbA1c Calculator (A1c ↔ eAG)

Enter HbA1c, average glucose in mg/dL or in mmol/L and get the other two, plus the IFCC value in mmol/mol.

Related tools

All Medical & clinical tools →
Blood Donation Time CalculatorFind your next eligible donation date by donation type, using either the American Red Cross or the French EFS intervals.Blood Pressure Category CalculatorClassify a reading with the ACC/AHA 2017 or the European ESC/ESH scale, plotted on a chart, with mean arterial pressure and pulse pressure.Blood Sugar Converter (mg/dL ↔ mmol/L)Convert blood glucose between mg/dL and mmol/L in both directions, and see where the value falls against the ADA reference bands.Blood Type CalculatorPredict a child's possible ABO and Rh blood types, with probabilities, from both parents' blood groups.Heart Disease Risk CalculatorEstimate your 10-year risk of heart attack and stroke with the 2013 ACC/AHA Pooled Cohort Equations (ASCVD), from age, sex, cholesterol, blood pressure and risk factors.Insulin Sensitivity Factor CalculatorEstimate your correction factor from the total daily dose with the 1500/1700/1800/2000 rule, in mg/dL or mmol/L, plus an optional correction dose.Blood alcohol calculatorEstimate your blood alcohol concentration (BAC) with the Widmark formula.BMR calculatorEstimate your Basal Metabolic Rate (Mifflin-St Jeor).

Open HbA1c Calculator (A1c ↔ eAG) and you get an answer straight away, with no account to create. Its place is under Medical & clinical; Blood Donation Time Calculator and Blood Pressure Category Calculator answer the questions closest to this one.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What is HbA1c Calculator (A1c ↔ eAG)?

Enter HbA1c, average glucose in mg/dL or in mmol/L and get the other two, plus the IFCC value in mmol/mol.

When would I actually use this?

Reading one HbA1c in the units the other laboratory uses, and turning it into the average blood glucose it corresponds to — the number that makes a percentage mean something day to day.

What is the most common mistake?

Treating the estimated average glucose as a measurement. It is a regression through a study population: two people with the same HbA1c can have genuinely different average glucose, and anything that shortens red-cell life — anaemia, haemoglobin variants, pregnancy, recent transfusion — moves the HbA1c without the glucose having moved.

Is there a tool for the next step?

Blood Pressure Category Calculator is the closest one after this: Classify a reading with the ACC/AHA 2017 or the European ESC/ESH scale, plotted on a chart, with mean arterial pressure and pulse pressure.

What else is worth having open alongside it?

Blood Sugar Converter (mg/dL ↔ mmol/L) and Blood Type Calculator — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

Two published equations, both named on the page. HbA1c to estimated average glucose is the ADAG study (Nathan et al., Diabetes Care 2008;31:1473-1478): eAG = 28.7 × A1c − 46.7. DCCT/NGSP percent to IFCC mmol/mol is the IFCC master equation: mmol/mol = (DCCT % − 2.15) × 10.929. The diagnostic thresholds are the American Diabetes Association's Standards of Care.

Further reading

All guides →
ExplainerHbA1c to Average Blood Sugar: The Full Conversion TableAn HbA1c of 7 percent corresponds to an average glucose of about 154 mg/dL, or 8.5 mmol/L, or 53 mmol/mol. Here is the whole table, the formulas behind it, and when the number cannot be trusted.ExplainerHow Heart Disease Risk Scores Work — and Why They Disagree About YouFramingham, SCORE2 and the pooled cohort equations use overlapping but different inputs and were calibrated on different populations, so the same person gets three different percentages. Here is what each one asks for and what the number means.ComparisonBiological Age vs Chronological Age: What Each One Actually MeasuresChronological age is exact. Biological age is not one thing but three — epigenetic clocks, blood-marker scores and lifestyle quizzes — and only the first two have published validation. Here is how to tell which one you are looking at.ExplainerHow Blood Type Is Inherited: The Full Parent-to-Child TableEach parent passes on one ABO allele — A, B or O — and Rh follows a separate gene. Here is every parent combination, which child types it can and cannot produce, and why this is not a paternity test.ExplainerHow Long Does Alcohol Stay in Your System?The body clears roughly one standard drink per hour. See how long alcohol stays in blood, breath and urine — and why you can't rush it.ExplainerThe Insulin Sensitivity Factor and the 1800 RuleThe correction factor says how far one unit of insulin moves glucose, and the classical estimate is 1800 divided by the total daily dose in mg/dL — or 100 divided by it in mmol/L. Those are the same rule, and here is the arithmetic that proves it, plus why stacking is the error that actually hurts.