Blood Pressure Calculator — BP Classification & MAP
Enter your systolic (top) and diastolic (bottom) blood pressure readings to see your AHA/ACC 2017 classification — from Normal to Hypertensive Crisis — plus mean arterial pressure (MAP) and pulse pressure.
mmHg
mmHg
Stage 1 Hypertension — Lifestyle changes recommended; medication may be considered.
- 1
Pulse pressure
120 − 80 = 40 - 2
Mean arterial pressure (MAP)
80 + 40 ÷ 3 = 93.3Diastole lasts ~2× longer than systole, so MAP ≈ diastolic + one-third of pulse pressure.
How does this calculator work?
MAP = diastolic + (systolic − diastolic)/3; pulse pressure = systolic − diastolic. Normal blood pressure is below 120/80 mmHg (AHA/ACC 2017). Stage 1 hypertension starts at 130/80, Stage 2 at 140/90, and a reading above 180/120 is a hypertensive crisis requiring immediate care.
Formula
How this is calculated
Blood pressure is measured as two numbers: systolic pressure (the peak when the heart contracts and ejects blood) over diastolic pressure (the trough when the heart relaxes and refills). Both are in millimetres of mercury (mmHg). A standard reading such as 120/80 mmHg means a systolic of 120 and a diastolic of 80.
The American Heart Association and American College of Cardiology 2017 guidelines define five categories: Normal (< 120/< 80), Elevated (120–129/< 80), Stage 1 Hypertension (130–139 or 80–89), Stage 2 Hypertension (≥ 140 or ≥ 90), and Hypertensive Crisis (> 180 or > 120). Classification is based on the higher of the two thresholds crossed.
Mean arterial pressure (MAP = diastolic + (systolic − diastolic)/3) is the average perfusion pressure during a cardiac cycle; a MAP of 70–100 mmHg is generally required to perfuse vital organs. Pulse pressure (systolic − diastolic) normally runs 40–60 mmHg; a wide pulse pressure (> 60 mmHg) can indicate aortic regurgitation or stiff arteries, while a narrow pulse pressure (< 40 mmHg) can signal low cardiac output. Diagnosis requires repeated measurements on separate occasions — a single reading is not sufficient.
Frequently asked questions
Hypertension is not diagnosed on a single reading. The AHA recommends averaging two or more readings on two or more occasions, taken after 5 minutes of rest. Home monitoring over several weeks gives the most reliable picture.
A hypertensive crisis is defined as systolic > 180 mmHg or diastolic > 120 mmHg. If accompanied by symptoms such as chest pain, shortness of breath, severe headache, or vision changes, it is a hypertensive emergency requiring immediate hospital care.
MAP represents the average pressure throughout the cardiac cycle and reflects organ perfusion pressure. Critical-care targets typically aim for a MAP ≥ 65 mmHg (or 70–100 mmHg for stable patients). It is calculated as diastolic + one-third of the pulse pressure because diastole lasts longer than systole.
TG we-Calculate Editorial Team. (2026). Blood Pressure Calculator — BP Classification & MAP [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/blood-pressure-calculator
TG we-Calculate Editorial Team. "Blood Pressure Calculator — BP Classification & MAP." TG we-Calculate. 2026. https://we-calculate.com/calculator/blood-pressure-calculator.
TG we-Calculate Editorial Team, "Blood Pressure Calculator — BP Classification & MAP," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/blood-pressure-calculator
@misc{wecalculate_blood_pressure_calculator, title = {Blood Pressure Calculator — BP Classification & MAP}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/blood-pressure-calculator}}, year = {2026}, note = {TG we-Calculate} }
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