Fasting Blood Sugar Range Evaluator
Check whether your morning fasting glucose reading is normal, prediabetic (impaired fasting glucose), or indicative of diabetes.
Fasting Glucose Evaluator
Measured after an overnight fast of at least 8 hours.
115 mg/dL (6.4 mmol/L) indicates Impaired Fasting Glucose
Fasting levels between 100 and 125 mg/dL meet the diagnostic criteria for prediabetes. Lifestyle interventions can frequently normalize this.
Clinical Guidelines & References: Diagnosis and Classification of Diabetes Mellitus (World Health Organization (WHO) & ADA)
See when your blood sugar tends to run high
Insights in T1dApp show your time in range and your daily pattern, hour by hour.
iOS App Store
T1dApp
Apple Health sync · Dexcom & Libre
Clinical Guidelines & Practical Guide
Understanding how this metric fits into comprehensive diabetes and glycemic management is critical for avoiding complications. This calculator uses published formulas and the ranges set out in guidelines such as the American Diabetes Association (ADA) Standards of Care. The sources are listed on this page.
Why This Calculation Matters
Blood sugar is dynamic and influenced by digestion, stress hormones, illness, and medication timing. Tracking standardized metrics prevents emotional decision-making and dangerous insulin stacking.
Standard Clinical Targets
For non-pregnant adults with diabetes: Fasting glucose 80–130 mg/dL (4.4–7.2 mmol/L), post-meal peak < 180 mg/dL (10.0 mmol/L), and A1C < 7.0% (53 mmol/mol) unless individualized by a provider.
When to Contact Your Physician
- Readings repeatedly over 250 mg/dL (13.9 mmol/L) accompanied by moderate or large urine/blood ketones.
- Unexplained, recurrent hypoglycemia (< 70 mg/dL / 3.9 mmol/L) or any hypoglycemic episode requiring third-party assistance.
- Planning pregnancy, surgery, or adjusting long-acting basal insulin regimens.
Medical Disclaimer: This digital calculator is an educational and informational tool intended to support healthy living and data logging. It is not medical software, an automated dosing algorithm, or a substitute for personal clinical judgment. Always consult an endocrinologist or certified diabetes educator before adjusting medication dosages.
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Evaluate any casual blood glucose reading taken without fasting against ADA clinical thresholds and urgent symptom markers.
Companion app for iPhone
Snap your meals and see what they do to your blood sugar
T1dApp turns food photos and glucose readings into clear, everyday patterns. Get carbs in seconds, an estimate of your blood sugar 2 hours later, and Dexcom and Libre readings through Apple Health.
- Snap meals with AI: see carbs, calories, and an expected 2-hour glucose range.
- Apple Health sync: import Dexcom and FreeStyle Libre CGM readings automatically.
- Meal impact insights: see which foods spike your blood sugar and which barely move it.
- Estimated A1c & reports: export clean PDF or CSV summaries to hand your care team.
iPhone & iPad · Built for Type 1, Type 2, and Prediabetes
