Fasting Blood sugar formula Blood Glucose If you get up in the morning and measure your blood glucose that's called your 'fasting blood glucose'. This is the most important measure of your blood glucose to indicate if you have diabetes or not. It's really simple, just take the measurement and compare it to the chart above. If a healthy person measures their fasting blood glucose they'll get a reading of between 70 and 90 mg/dl (US measurements) or between 3.9 and 5.0 Nerve renew mmol/l (the standard everywhere else). That's called 'normal'.