Here is how to make sense of your numbers: Normal blood pressure: According to the American Heart Association, blood pressure is in the normal range if it's below 120/80 mm Hg. Prehypertension: Between 120/80 mm Hg and 139/89 mm Hg. Stage 1 high blood pressure: Between 140/90 mm Hg and 159/99 mm Hg.