Blood Sugar
Conversion Chart

Instantly convert between mg/dL, mmol/L, and estimated HbA1c.

Converter

Used by US, Japan

Used by UK, Australia, Canada, Singapore, most European countries

~3 month average blood sugar

Type a value in any field and the other two update automatically. The mg/dL and mmol/L values here represent average blood glucose, which is what HbA1c reflects. Estimated using the ADAG formula.

This tool is for educational purposes only and does not replace professional medical advice. Always consult your healthcare provider for diagnosis and treatment decisions.

Blood Glucose Conversion Chart

Average blood glucose values and their equivalents across units. HbA1c reflects your average blood sugar over ~3 months.

Avg. mg/dL Avg. mmol/L Est. HbA1c % Range
70 3.9 4.1% Normal
80 4.4 4.4% Normal
90 5.0 4.8% Normal
100 5.6 5.1% Normal
110 6.1 5.5% Normal
114 6.3 5.6% Normal
117 6.5 5.7% Prediabetes
120 6.7 5.8% Prediabetes
126 7.0 6.0% Prediabetes
131 7.3 6.2% Prediabetes
137 7.6 6.4% Prediabetes
140 7.8 6.5% Diabetes
154 8.6 7.0% Diabetes
170 9.4 7.5% Diabetes
183 10.2 8.0% Diabetes
200 11.1 8.6% Diabetes
240 13.3 10.0% Diabetes
300 16.7 12.1% Diabetes

Ranges classified by estimated HbA1c: Normal < 5.7%, Prediabetes 5.7–6.4%, Diabetes ≥ 6.5%.

What Do the Ranges Mean?

Low (Hypoglycemia)
< 70 mg/dL
< 3.9 mmol/L

Blood sugar is below the normal range. May cause shakiness, confusion, or dizziness. Eat fast-acting glucose to bring levels up.

Normal
HbA1c < 5.7%
~70 – 117 mg/dL · 3.9 – 6.5 mmol/L

Long-term blood sugar is in the healthy range. No action needed beyond routine checkups.

Prediabetes
HbA1c 5.7 – 6.4%
~117 – 140 mg/dL · 6.5 – 7.8 mmol/L

Blood sugar is higher than normal but below the diabetes threshold. Lifestyle changes (e.g., diet and exercise) can often reverse it.

Diabetes
HbA1c ≥ 6.5%
≥ 140 mg/dL · ≥ 7.8 mmol/L

An HbA1c of 6.5% or higher on two separate tests indicates diabetes. Medical management is recommended.

How the Conversions Work

mg/dL ↔ mmol/L

Both units measure blood glucose concentration. The US uses mg/dL; most other countries use mmol/L.

mmol/L = mg/dL ÷ 18.016

mg/dL = mmol/L × 18.016

Glucose → Est. HbA1c

HbA1c reflects ~3 months of average blood sugar. The ADAG study formula estimates HbA1c from mean glucose.

HbA1c = (mg/dL + 46.7) ÷ 28.7

mg/dL = (HbA1c × 28.7) − 46.7

Sources

Learn blood sugar management through play

Glycohero is an educational game that teaches you which foods raise or lower blood glucose and why.

Download on iOS