A1C vs home glucose: what a diary can and cannot show
Free printable blood sugar log (PDF)
A1C vs blood glucose (or hemoglobin A1C vs home finger-sticks) confuses almost everyone who starts a log. A1C is a laboratory test that reflects average blood glucose over roughly the past 2–3 months. A home glucose reading is one moment from a meter or CGM display. Blood Snap charts numbers you logged from home checks. It does not compute or replace an A1C.
What each number answers
- Home glucose: “What does my meter show right now (or at this tagged time)?”
- A1C: “What does the lab say about longer-term average?”
They can move in the same direction over months and still disagree on a given week. Only your clinician interprets both together.
What a home glucose diary is for
Fasting vs after-eating patterns, timing around meals or medicine your clinician set, and a PDF of recent checks for the visit. Build that record with a glucose manager / diary and glucose chart trends.
A1C vs fasting blood glucose
Fasting home checks are still point-in-time. They are not a mini-A1C. Do not average a week of Blood Snap entries and call it your A1C.
Hard limits
- No diagnosis from either number on this website.
- No insulin or medicine changes from a chart alone.
- CGM time-in-range reports are a different product class — see glucometer vs CGM.
Log home glucose in Blood Snap. Bring the diary to visits where A1C and meter history are discussed together — the app will not invent an A1C for you.
Educational information with public guideline citations. Not medical advice and not a diagnosis. Blood Snap is a personal wellness diary — not a medical device, blood pressure machine, glucometer, or CGM. Always follow your clinician's advice.