What is the normal range for blood sugar 3 hours after a meal (dinner)?

Depends: It depends on what you ate for dinner and what was your carbohydrate intake in the previous 3 days. There are not "normal" figures for the circumstance you described, however, if your blood sugar was higher than 140, it would be prudent to consult a doctor for fasting blood sugar and if needed, a glucose tolerance test. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.