What does your blood sugar reading mean?
Type in any reading — we show you where it sits on the official scales, fasting and after eating, in mg/dl and mmol/L.
mg/dl and mmol/L both work — values like 5.5 are read as mmol/L automatically.
Often checked (fasting): 90 100 110 117 126 140 160 200 All values
The official ranges
Normal, prediabetes, diabetes — the ADA chart explained without jargon, for fasting and post-meal readings.
Your private journal
Save readings on your device — chart your trend, print a sheet for your doctor, export anytime. Nothing is uploaded, ever.
When to act
Below 70 or above 250 mg/dl — the two situations where waiting is the wrong strategy, and what to do instead.
Guides
Normal blood sugar levels
The full classification chart — fasting, after meals and A1C — explained range by range, and why context changes what a number means.
Prediabetes: what your numbers mean
Fasting 100–125 mg/dl is a warning, not a verdict. What the diagnosis means and the evidence that it can be reversed.
Fasting blood sugar
Why the fasting number is the reference measurement, how to take it correctly, and what pushes it up overnight.
Blood sugar after eating
What a normal glucose curve after a meal looks like, when to measure, and why 140 and 200 mg/dl are the lines that matter.
mg/dL vs mmol/L
The US measures in mg/dl, most of the world in mmol/L. How to convert, and how to spot which unit a number is in.
A1C and blood sugar
How the 3-month average relates to daily readings, what eAG means, and why two people with the same A1C can have very different days.