Blood Pressure Calculator

For most adults, US guidelines call a reading below 120 systolic AND below 80 diastolic mmHg "normal". Readings from 120–129 systolic with diastolic under 80 are "elevated", and 130/80 mmHg or higher falls into stage 1 or stage 2 hypertension. These thresholds come from the 2017 AHA/ACC guideline used in the United States; European guidelines stage slightly differently (140/90 mmHg as the hypertension threshold).

Sit in a chair with back support for 5 minutes before measuring, feet flat on the floor, arm supported at heart level, cuff on bare upper arm. Avoid caffeine, exercise, and smoking for 30 minutes beforehand, and empty your bladder first. Take two or three readings a minute apart and average them. Use a validated upper-arm cuff device — wrist and finger cuffs are less reliable — and check the cuff size matches your arm.

Some people read higher in a medical setting than at home because the environment makes them anxious — this is called white-coat effect or white-coat hypertension. It is one reason guidelines rely on averages across multiple occasions, and why home monitoring is so useful. The reverse also exists: masked hypertension, where readings look fine in the office but run high at home.

For home monitoring of diagnosed or suspected hypertension, a common routine is twice per day — morning and evening — for the first week, then a few times per week at consistent times. If your readings are normal and you have no risk factors, checking every few months is a reasonable habit. Follow whatever schedule your clinician gives you; it takes priority over general advice.

Contact a clinician promptly if a reading above 180/120 mmHg repeats after 5 minutes of rest, or if you get high readings together with symptoms such as chest pain, shortness of breath, severe headache, vision changes, or weakness — that warrants immediate medical attention. Also make an appointment if readings repeatedly land in stage 2 (140/90 or higher) even without symptoms, or if stage 1 readings persist across several occasions.

No. It classifies a single reading against published thresholds and computes two related values (MAP and pulse pressure). Hypertension is diagnosed by averaging multiple properly measured readings across multiple occasions, and by a clinician who knows your history — thresholds and targets differ with diabetes, kidney disease, pregnancy, and age. Use this tool to understand your numbers and track trends, not to diagnose yourself.