Blood Sugar Converter

What Is Blood Sugar (Glycemia)?

Blood sugar (blood glucose) refers to the concentration of glucose circulating in your blood. Glucose is the primary source of energy for your body's cells and is obtained from the food you eat — particularly carbohydrates. The hormone insulin, produced by the pancreas, helps cells absorb glucose from the blood.

Maintaining blood sugar within a healthy range is critical. Consistently high blood sugar (hyperglycemia) can lead to diabetes and its complications, while dangerously low blood sugar (hypoglycemia) can cause seizures, loss of consciousness, and death.

Blood Sugar Units: mg/dL vs. mmol/L

Blood glucose can be measured in two units:

• mg/dL (milligrams per deciliter) — Used in the United States, Japan, France, Egypt, and some other countries
• mmol/L (millimoles per liter) — Used in the United Kingdom, Canada, Australia, China, and most other countries

The factor 18.0182 comes from the molecular weight of glucose (180.16 g/mol) divided by 10.

Normal Blood Sugar Levels

Test Type	Normal	Prediabetes	Diabetes
Fasting Glucose	< 100 mg/dL (< 5.6 mmol/L)	100–125 mg/dL (5.6–6.9 mmol/L)	≥ 126 mg/dL (≥ 7.0 mmol/L)
2-hour OGTT	< 140 mg/dL (< 7.8 mmol/L)	140–199 mg/dL (7.8–11.0 mmol/L)	≥ 200 mg/dL (≥ 11.1 mmol/L)
Random Glucose	< 140 mg/dL (< 7.8 mmol/L)	—	≥ 200 mg/dL + symptoms (≥ 11.1 mmol/L)
HbA1c	< 5.7%	5.7–6.4%	≥ 6.5%

What Is HbA1c?

Hemoglobin A1c (HbA1c) measures the percentage of hemoglobin in your blood that has glucose attached to it. Because red blood cells live for about 120 days, HbA1c reflects your average blood sugar over the past 2–3 months, making it the best indicator of long-term glucose control.

The approximate relationship between HbA1c and average blood glucose is:

HbA1c (%)	Estimated Avg. Glucose (mg/dL)	Estimated Avg. Glucose (mmol/L)
5.0	97	5.4
5.5	111	6.2
6.0	126	7.0
6.5	140	7.8
7.0	154	8.6
8.0	183	10.2
9.0	212	11.8
10.0	240	13.4

How to Maintain Healthy Blood Sugar

• Diet: Choose whole grains, vegetables, lean proteins. Limit refined sugars and processed carbohydrates. Eat regular, balanced meals.
• Exercise: At least 150 minutes of moderate aerobic activity per week. Physical activity improves insulin sensitivity.
• Weight management: Losing 5–7% of body weight can significantly reduce diabetes risk in prediabetic individuals.
• Monitoring: Regular blood sugar testing if diabetic or at risk. Know your HbA1c.
• Medication: Take prescribed diabetes medications or insulin as directed.
• Sleep: Poor sleep can affect insulin resistance. Aim for 7–9 hours.
• Stress management: Chronic stress raises cortisol, which can increase blood sugar.

Hypoglycemia (Low Blood Sugar)

Blood sugar below 70 mg/dL (3.9 mmol/L) is considered hypoglycemia. Symptoms include shakiness, sweating, confusion, rapid heartbeat, hunger, and irritability. Severe hypoglycemia below 54 mg/dL (3.0 mmol/L) requires immediate treatment with fast-acting glucose. This is a medical emergency.

Frequently Asked Questions

What is a normal fasting blood sugar?

A normal fasting blood sugar is below 100 mg/dL (5.6 mmol/L). Values between 100–125 mg/dL indicate prediabetes, and 126 mg/dL or higher on two separate tests indicates diabetes.

Can sugar turn into alcohol in the body?

No. Humans lack the specific enzymes (zymase) necessary for alcoholic fermentation. Yeast can convert sugar to alcohol, but this process does not occur in the human body.

Why do different countries use different units?

The US uses mass concentration (mg/dL) which measures the weight of glucose per volume of blood. Most other countries use molar concentration (mmol/L) which measures the number of glucose molecules per volume. Both are equally valid; the difference is purely historical and regional.