In the Chrome Web StoreA1C Calculator help and support
This page covers common A1C Calculator problems with the side panel, conversions, the history log, import and export. If your problem isn't listed, email support with the details below.
First things to try
- Click the extension icon to open the calculator in Chrome's side panel.
- Type a value in one field only and let the other three fill in.
- Make a JSON backup from History before you delete entries or change computers.
- Set the export date range to All Time if an export finds no data.
Common problems and fixes
A1C Calculator side panel doesn't open
Clicking the toolbar icon opens the calculator in Chrome's side panel, which needs Chrome 114 or later. Update Chrome if nothing happens, or open the side panel from Chrome's toolbar and choose A1C Calculator from its list.
Estimated average glucose doesn't match my lab report
Small differences come from rounding: the calculator uses the ADAG formula eAG = 28.7 × A1C − 46.7, shows mg/dL as a whole number and mmol/L and A1C % with one decimal. A lab may round differently or measure glucose another way. eAG is an estimate, not a diagnosis; ask your doctor about your own results.
Save to History button is grayed out
Saving needs an A1C value, so type a number in any of the four fields first. The date can't be in the future: the date picker and the next-day arrow stop at today.
What do Normal, Prediabetes and Diabetes on the gauge mean?
They label the number you typed using the ADA A1C ranges: below 5.7% Normal, 5.7% to 6.4% Prediabetes, 6.5% or higher Diabetes. A calculator result is not a diagnosis. Only your doctor can interpret your results.
Import failed: Invalid file format or No valid entries found
Import accepts only a JSON backup, such as the file made by Export as JSON; CSV and PDF files can't be imported. Each entry needs a date and an A1C value. Entries already in your history are skipped and the panel shows how many duplicates were skipped.
Export says No data in selected range
Exports use the date range selected in the export menu, and none of your entries fall inside it. Pick All Time or a wider Custom Range and export again.
I deleted an entry by mistake
Deleting an entry takes effect at once and can't be undone. You can get it back only by importing a JSON backup made before you deleted it.
Move my A1C history to another computer
Your log is not synced between devices, so move it with a backup file. On the old computer open History and use Export as JSON; on the new one install the extension, open History, click Import and pick the file.
Add my name to the PDF report
Open Settings and type it in Patient Name (for PDF reports). The name is printed on PDF reports you create from History or Chart.
Your data
Your results and settings (theme, time format, patient name, history display) are kept in the extension's local storage in this Chrome profile only; nothing is synced or sent anywhere. To back up, open History and use Export as JSON (a1c-backup-YYYY-MM-DD.json). To clear the log, delete entries one by one or remove the extension, which deletes all its data.
When you write to us
- The value and unit you typed, and the numbers shown in the other three fields.
- Which tab you were on (Calc, History, Chart or Ref) and the date range selected for export.
- For import problems, the exact error message and how the file was made. You don't need to send the file or your health data.
- The extension name and its version from
chrome://extensions. - Your Chrome version from
chrome://settings/helpand your operating system. - What you did, what you expected and what happened instead.
- A screenshot, if the problem is visible on the screen.