Please read first: what this page can and cannot do
This page carries educational information only. It is not medical advice, it does not diagnose any condition, and it cannot tell you what your result means for your health. A laboratory result belongs in a conversation with your own doctor, who knows your history, your other tests, and your medicines. Read everything below as an explanation of numbers, and take every personal decision to that conversation.
The honesty limit sits at the top on purpose. HbA1c numbers carry real weight in a family's life, and a converter that hides its limits behind the answer would fail the reader at the exact moment the reader trusts it most. The tool above converts. The bands below describe how the test is classified. Neither one diagnoses you.
What HbA1c measures and what eAG adds
HbA1c (glycated hemoglobin) is a blood test that reports the share of hemoglobin carrying glucose. Glucose attaches to hemoglobin for the life of the red blood cell, about 120 days, so the percentage reflects average glucose across roughly the past three months. The result arrives as a percentage, and a percentage is where most readers stall, because no home meter speaks in percentages.
Estimated average glucose (eAG) is the translation. The eAG takes the HbA1c percentage and restates it in the units a meter uses, mg/dL in Pakistan and the United States, mmol/L in the United Kingdom and much of Europe. An HbA1c of 7.0 percent becomes an eAG of 154 mg/dL, a number that can sit beside a meter diary and be compared with it honestly, hour structure and all.
The two summaries describe the same season from different instruments. A meter diary samples the moments a person chooses to test, usually fasting and before meals. The HbA1c samples everything, including the hours after meals that home testing rarely touches. A gap between a home average and the eAG is therefore a normal finding with a known cause, and the articles below work through it in detail. I know that gap personally: at my father's table it measured 35 points, and every point of it came from hours the diary never visited.
Each whole percentage step raises the eAG by about 29 mg/dL, the step the ADAG formula fixes. The even staircase is the visual signature of a linear formula, and it is why one number memorized at one level, 7 percent equals 154, lets a reader estimate the whole neighborhood within a few points.
The full HbA1c to eAG conversion table
The table below converts HbA1c from 4.5 to 15 percent in half-point steps into eAG in mg/dL and in mmol/L, computed with the ADA formula printed on this page. Keep the table beside a lab report and the percentage stops being an abstraction.
| HbA1c (%) | eAG (mg/dL) | eAG (mmol/L) | HbA1c (%) | eAG (mg/dL) | eAG (mmol/L) |
|---|---|---|---|---|---|
| 4.5 | 82 | 4.6 | 10.0 | 240 | 13.3 |
| 5.0 | 97 | 5.4 | 10.5 | 255 | 14.1 |
| 5.5 | 111 | 6.2 | 11.0 | 269 | 14.9 |
| 6.0 | 126 | 7.0 | 11.5 | 283 | 15.7 |
| 6.5 | 140 | 7.7 | 12.0 | 298 | 16.5 |
| 7.0 | 154 | 8.5 | 12.5 | 312 | 17.3 |
| 7.5 | 169 | 9.3 | 13.0 | 326 | 18.1 |
| 8.0 | 183 | 10.1 | 13.5 | 341 | 18.9 |
| 8.5 | 197 | 10.9 | 14.0 | 355 | 19.7 |
| 9.0 | 212 | 11.7 | 14.5 | 369 | 20.5 |
| 9.5 | 226 | 12.5 | 15.0 | 384 | 21.3 |
Whole and half points cover the reports families actually bring home. A report value between rows, such as 7.4, converts exactly in the tool above rather than by guessing between table lines: 7.4 percent gives an eAG of about 166 mg/dL.
The diagnostic bands, stated as information
The table below states the bands the American Diabetes Association uses to classify an HbA1c result. The bands describe the test. A diagnosis is a clinical act that uses confirmatory testing and the full picture, and it belongs to your doctor.
| HbA1c | Band | eAG at the band edges (mg/dL) |
|---|---|---|
| Below 5.7% | Normal range for the test | Below 117 |
| 5.7% to 6.4% | Prediabetes range | 117 to 137 |
| 6.5% and above | Diabetes range, one diagnostic threshold among several | 140 and above |
Educational information only, not medical advice. A value inside a band is a reason to talk with your doctor about what the result means for you, how often to retest, and which other tests belong in the picture. No table on the internet, including this one, can carry that conversation for you.
The ADA also lists an HbA1c goal below 7 percent for many adults who live with diabetes, set individually with the treating doctor. A goal is a treatment target agreed with a clinician, never a grade a reader assigns at home, and goals differ for older adults, for children, and in pregnancy.
The formula, and where it comes from
The converter applies the formula from the A1c-Derived Average Glucose (ADAG) study: eAG in mg/dL equals 28.7 times the HbA1c percentage, minus 46.7. The companion formula gives eAG in mmol/L directly: 1.59 times the percentage, minus 2.59. The ADAG researchers built both lines by matching HbA1c results against thousands of meter readings from the same people, which is why the formula carries a study behind it rather than a convention.
Check one row by hand and the whole table earns your trust or loses it fairly. HbA1c 7.0: 28.7 times 7 is 200.9; minus 46.7 gives 154.2, which the table rounds to 154 mg/dL. HbA1c 9.0: 28.7 times 9 is 258.3; minus 46.7 gives 211.6, rounded to 212. Every row on this page survives the same ten-second audit, and the tool runs the identical arithmetic.
One caution belongs with the formula. An eAG is an average, and real glucose moves above and below any average across a day. Two people can share an HbA1c and live very different daily patterns, one steady and one swinging. The average is a summary for a conversation with a clinician, and continuous monitoring summaries such as time in range describe the pattern the average hides, a comparison the articles below develop.
The mg/dL and mmol/L bridge
Glucose wears two units in the world, and families meet both. Pakistan and the United States print mg/dL. The United Kingdom, much of Europe, and many meters bought in the Gulf print mmol/L. The bridge between them is one division: mmol/L equals mg/dL divided by 18.01559, and many printed charts round the factor to 18, which is why a chart can differ from this tool in the last decimal.
The second tab of the tool above runs that bridge for a single reading, in both directions. The anchors worth memorizing are few: 70 mg/dL is 3.9 mmol/L, 100 is 5.6, 126 is 7.0, 180 is 10.0, and 200 is 11.1. A reading of 5.6 on an imported meter frightened one family in my own circle before anyone noticed the unit, and the article below tells that evening in full.
Three reports worked in full
A report prints HbA1c 7.4 percent. The formula gives 28.7 times 7.4, which is 212.38, minus 46.7, which is about 166 mg/dL, and 9.2 mmol/L by the companion formula. Against a meter diary full of fasting readings near 130, the 166 looks like an accusation. The reading of the number is calmer: the diary saw mornings, and the blood saw everything, including lunches.
A routine checkup prints 5.8 percent. The eAG is about 120 mg/dL. The value sits one step inside the 5.7 to 6.4 prediabetes band, which describes elevated risk and a testing schedule, not a verdict. The prediabetes article below explains what the band does and does not claim, and why retesting on schedule beats worrying on schedule.
A report prints 9.0 percent beside a home average the family calculated at 170. The eAG is 212 mg/dL, and the gap of forty points has named causes to examine before any conclusion: post-meal hours missing from the home log, a meter drifting from calibration, or a condition that shifts the HbA1c itself, such as anemia. The interference article below lists the recognized causes with sources, exactly so a family can bring informed questions to the appointment rather than a settled fear.
Why I built this converter
My father's lab report came home with one number circled: HbA1c 7.4. Nobody at home could connect 7.4 to the fasting numbers around 130 that filled his meter diary, and the doctor's explanation, that his average sat near 166, settled the visit and unsettled the week. A percentage and a diary were describing one man's blood in two languages, and my family only spoke one of them.
I tried three online converters that week. One returned a value from a formula I could not find in any source. None offered mmol/L for the relative abroad who asked for the number in his unit. Each one presented its answer as a finished fact, with no formula to audit and no line about the limits of an estimate.
So this converter runs on the published ADA formula, prints the formula on the page, and carries the conversion table I later printed for my father's report file. The bands are labeled as information about the test, the disclaimer stands above the fold where a health page owes it, and the second tab exists because of a frightened phone call about a meter bought abroad. Tools earn trust by showing their work, and health tools owe more of that duty, not less.
His notebook said one average and his blood said another, because the notebook only ever saw mornings. For one month I logged his fasting readings and averaged them by hand, certain the lab had blundered. The lab had not blundered. My sampling had, and the gap between a fasting-only average and a three-month average is the single most useful thing this page can teach a family.
More guides on reading diabetes numbers
- What your HbA1c number means next to your daily meter readings
- The prediabetes range, 5.7 to 6.4: what this band actually describes
- Why HbA1c covers three months and not three weeks
- Fasting looks fine but HbA1c says higher: the post-meal gap
- How to read a diabetes lab report line by line
- Estimated average glucose and time in range: two different summaries
- When an HbA1c result can mislead: conditions that shift the number
- The mg/dL and mmol/L mix-up: reading a meter bought abroad
- Tracking HbA1c across a year: the table that keeps everyone honest
- Questions worth taking to your next diabetes appointment
Every guide in this set carries the same standing line as this page: educational information only, not medical advice, and results belong in a conversation with your own doctor.
Questions people ask about this page
Is eAG the same as a fasting reading?
No. A fasting reading is one moment, taken after a night without food, while eAG is the average of every hour across about three months, meals and nights included. A fasting figure therefore usually sits below the eAG from the same period, and the gap between them is normal rather than an error.
Why does my meter average differ from my eAG?
Most home averages rest on fasting and pre-meal checks, because those are the moments people test. The eAG also contains the hours after meals, which home logs rarely capture, so the lab average comes out higher. Testing patterns, meter accuracy, and red blood cell conditions also move the comparison, and a persistent wide gap is a question for your doctor.
How often is HbA1c tested?
The ADA recommends testing at least twice a year for people who are meeting their goals, and quarterly when therapy has changed or goals are not being met. Your doctor sets your own schedule, because the right interval depends on your treatment and your recent results.
Can anemia change an HbA1c result?
Yes. Conditions that change how fast red blood cells turn over, including several forms of anemia, some hemoglobin variants, kidney failure, and pregnancy, can push an HbA1c result up or down away from the true average. A result that disagrees with your daily readings deserves a conversation with your doctor, not a private adjustment of your medicine.
Which unit does Pakistan use, mg/dL or mmol/L?
Pakistan reports blood glucose in mg/dL, the same unit the United States uses. The United Kingdom and much of Europe report mmol/L, and a meter bought abroad may arrive set to mmol/L. The second tab of the tool above converts a single reading between the two, dividing or multiplying by 18.01559.
Is a single HbA1c result enough to diagnose diabetes?
No. ADA guidance describes confirmatory testing, because one result can be shifted by lab variation or by a condition that affects red blood cells. A clinician makes the diagnosis from the full picture. This page is educational information only and never a diagnosis.
Facts, checked against trusted sources
- The eAG formula comes from the A1c-Derived Average Glucose (ADAG) study, which matched HbA1c values to thousands of meter readings: eAG (mg/dL) = 28.7 × A1c − 46.7. Source: Nathan DM et al., Diabetes Care 2008, American Diabetes Association
- The American Diabetes Association diagnostic thresholds for HbA1c are 6.5 percent or above for diabetes and 5.7 to 6.4 percent for prediabetes. Source: American Diabetes Association, Diabetes Diagnosis
- The ADA lists an HbA1c goal of below 7 percent for many adults with diabetes, set individually with the treating doctor. Source: American Diabetes Association, Standards of Care in Diabetes
- HbA1c reflects average glucose over roughly the past three months, because glucose attaches to hemoglobin for the life of the red blood cell, about 120 days. Source: American Diabetes Association, Understanding A1C
