Enter your systolic and diastolic readings for instant AHA classification, risk level and practical health guidance.
A Blood Pressure Calculator helps you interpret your blood pressure readings using the American Heart Association (AHA) and ACC 2017 guidelines. By entering your systolic (upper) and diastolic (lower) numbers, you can instantly understand which category your blood pressure falls into and what action to take.
Blood pressure is the force of blood pushing against artery walls. It is measured in millimeters of mercury (mmHg) and recorded as two numbers: systolic (when the heart contracts) over diastolic (when the heart relaxes). High blood pressure (hypertension) is often called the "silent killer" because it usually has no symptoms but significantly increases risk of stroke, heart attack and kidney disease.
| Category | Systolic | Diastolic | Action |
|---|---|---|---|
| Normal | <120 | <80 | Maintain lifestyle |
| Elevated | 120–129 | <80 | Lifestyle changes |
| Stage 1 HTN | 130–139 | 80–89 | Lifestyle + possible meds |
| Stage 2 HTN | ≥140 | ≥90 | Medication required |
| Crisis | >180 | >120 | Emergency care |
Like the Ponderal Index, blood pressure assessment compares two measurements to derive a meaningful health indicator. Mean Arterial Pressure (MAP = diastolic + 1/3 pulse pressure) is the average pressure throughout the cardiac cycle and is used clinically to assess perfusion to vital organs. Normal MAP is 70–100 mmHg.
Enter your systolic and diastolic readings from a recent blood pressure measurement. Take readings after 5 minutes of rest, while sitting with feet flat on the floor. Avoid caffeine, exercise and smoking for 30 minutes before measurement. Optionally enter heart rate for additional classification.
A single reading is not sufficient to diagnose hypertension. Blood pressure varies throughout the day and with stress, activity and caffeine. Diagnosis requires multiple readings taken on different occasions. White coat hypertension (elevated readings in a medical setting) is common. Always consult a doctor for diagnosis and treatment.