Blood Sugar Calculator

Health

Convert blood sugar levels between mg/dL and mmol/L and interpret the result against standard ranges.

Formula

mmol/L = mg/dL ÷ 18.0182; mg/dL = mmol/L × 18.0182
  • Normal fasting glucose: 70–99 mg/dL (3.9–5.5 mmol/L).
  • Normal 2-hour post-meal: <140 mg/dL (<7.8 mmol/L).
  • These are general guidelines — consult your doctor for personal thresholds.

Fasting glucose 100 mg/dL

Inputs
  • Blood Glucose Value: 100
  • Unit: mgdl
  • When Measured: fasting

100 mg/dL = 5.55 mmol/L. Fasting: at the upper end of normal (borderline).

Frequently asked questions

What is normal blood sugar?
Fasting: 70-99 mg/dL. 2 hours after eating: <140 mg/dL. These are general guidelines.
What is pre-diabetes?
Fasting glucose 100-125 mg/dL or 2-hour post-meal 140-199 mg/dL.
Why do units differ by country?
US uses mg/dL; Canada, UK, and most of Europe use mmol/L. Same measurement, different scale.
Is this a diagnostic tool?
No — for educational purposes only. Consult your doctor for diagnosis and treatment.