Blood Pressure Calculator

Blood pressure is the force of blood against the walls of the arteries. It is written as systolic over diastolic, in millimeters of mercury (mmHg). Systolic is the pressure when the heart beats; diastolic is the pressure when the heart rests between beats.

American Heart Association adult categories: Normal (systolic less than 120 AND diastolic less than 80), Elevated (systolic 120 to 129 AND diastolic less than 80), Stage 1 hypertension (systolic 130 to 139 OR diastolic 80 to 89), Stage 2 hypertension (systolic 140 or higher OR diastolic 90 or higher), Hypertensive crisis (systolic above 180 AND/OR diastolic above 120).

No. A single reading can be affected by stress, caffeine, exercise, cuff fit, and how you are sitting. Clinicians look at multiple readings over time, taken under similar conditions, and may also use home or ambulatory monitoring. Use this calculator as a category check for one reading at a time, not as a diagnosis.

Systolic above 180 mmHg and/or diastolic above 120 mmHg. Wait one minute and retake. If still that high, contact a clinician. If symptoms like chest pain, shortness of breath, weakness, vision changes, or trouble speaking are present, call emergency services right away.

No. Children, teens, and pregnant people have different reference ranges. For pediatric blood pressure use age-, sex-, and height-adjusted percentile tables. For pregnancy, talk to a clinician about your specific reference range and any monitoring plan.

Activity level, salt intake, weight, alcohol use, sleep, stress, smoking, and medications all influence blood pressure. Some changes (more activity, less sodium, more sleep) move readings down for many people. Discuss any changes with a clinician, especially if you take medications.

Less than 120/80 mmHg is considered normal by the American Heart Association. Slightly higher (120-129 systolic with normal diastolic) is "elevated" and a warning sign. Below 90/60 may indicate low blood pressure (hypotension), though this is only concerning if you have symptoms like dizziness or fainting.

Seek immediate medical care if your reading is above 180/120 (hypertensive crisis), especially with chest pain, shortness of breath, vision changes, or numbness. Schedule a regular doctor visit if you consistently read above 130/80 — this is the threshold for Stage 1 hypertension. A single high reading isn't an emergency, but multiple consistent readings need medical attention.

Often yes, especially in Stage 1 (130-139/80-89). Lifestyle changes including the DASH diet, regular exercise, weight loss, sodium reduction, and stress management can lower systolic blood pressure by 5-20 points. Many people in Stage 1 can normalize their numbers through lifestyle alone. Stage 2 hypertension (140+/90+) usually requires medication in addition to lifestyle changes.

No. This calculator provides educational information about blood pressure categories based on AHA guidelines. Actual diagnosis and treatment require medical evaluation, including multiple readings over time, blood tests, and personalized risk assessment. Use this calculator to understand your numbers, but consult a doctor for diagnosis and treatment decisions.