Blood Glucose Levels Chart (mg/dL and mmol/L)

Blood glucose changes all day — with meals, activity, sleep, stress and medication. This chart shows what counts as normal, prediabetes and diabetes, the usual targets when you have diabetes, and the levels that need action, in both mg/dL and mmol/L.

Blood glucose levels chart (mg/dL and mmol/L)

Level	Fasting	2 h after eating / glucose drink	HbA1c
Low (hypoglycemia)	below 70 mg/dL (3.9 mmol/L); level 2 below 54 mg/dL (3.0 mmol/L)		—
Normal	70–99 mg/dL 3.9–5.5 mmol/L	below 140 mg/dL below 7.8 mmol/L	below 5.7%
Prediabetes	100–125 mg/dL 5.6–6.9 mmol/L	140–199 mg/dL 7.8–11.0 mmol/L	5.7–6.4%
Diabetes	126 mg/dL or more 7.0 mmol/L or more	200 mg/dL or more 11.1 mmol/L or more	6.5% or more

Diagnostic thresholds of the American Diabetes Association. A diagnosis needs two abnormal results (the same test repeated, or two different tests) unless symptoms are clear.

Targets when you have diabetes

Measurement	Target for most adults
Before meals	80–130 mg/dL (4.4–7.2 mmol/L)
1–2 hours after the start of a meal	below 180 mg/dL (10.0 mmol/L)
HbA1c	below 7% (53 mmol/mol)
Time in range (CGM, 70–180 mg/dL)	more than 70% of the day
Time below range (below 70 mg/dL)	less than 4%; below 54 mg/dL less than 1%

Targets are agreed individually. Older adults or people with frequent lows often aim higher; pregnancy needs tighter targets.

Average glucose and HbA1c

HbA1c	Estimated average glucose
5.0%	97 mg/dL (5.4 mmol/L)
5.5%	111 mg/dL (6.2 mmol/L)
6.0%	125 mg/dL (6.9 mmol/L)
6.5%	140 mg/dL (7.8 mmol/L)
7.0%	154 mg/dL (8.5 mmol/L)
7.5%	169 mg/dL (9.4 mmol/L)
8.0%	183 mg/dL (10.2 mmol/L)
9.0%	212 mg/dL (11.8 mmol/L)
10.0%	240 mg/dL (13.3 mmol/L)
11.0%	269 mg/dL (14.9 mmol/L)
12.0%	298 mg/dL (16.5 mmol/L)

ADAG study formula: average glucose (mg/dL) = 28.7 × HbA1c − 46.7.

What affects your blood glucose

Food: carbohydrates raise glucose most; fiber, protein and fat slow the rise.
Activity: muscles use glucose during and for hours after exercise — lows can occur later, especially overnight. Very intense exercise can briefly raise glucose.
Medication: insulin and sulfonylureas lower glucose (and can cause lows); steroids such as prednisone raise it.
Illness and stress: stress hormones raise glucose, sometimes a lot.
Sleep: short or poor sleep worsens insulin sensitivity the next day.
Hormones: the dawn phenomenon, menstrual cycle and pregnancy all shift levels.
Alcohol: can cause delayed lows, particularly with insulin.

How to keep levels in range

Regular meals with plenty of vegetables and fiber, daily activity, enough sleep and taking medication as prescribed form the base. Testing at the right times — or wearing a CGM — shows how your body reacts. See How to Measure Blood Sugar: Meter, CGM, Lab and Blood Glucose Control: How It Works.

Look up any number on our values page.

Educational content only; not medical advice. Follow the treatment plan you have agreed with your doctor or diabetes team. In an emergency, call 911 (US) or your local emergency number.

Blood Glucose Levels Chart (mg/dL and mmol/L)