Blood Pressure Calculator
HealthClassify your blood pressure reading using the 2017 AHA/ACC guideline categories and calculate mean arterial pressure (MAP) from systolic and diastolic values.
Systolic Pressure
mmHg
60 mmHg250 mmHg
Diastolic Pressure
mmHg
40 mmHg150 mmHg
BP Category
—
Mean Arterial Pressure
0 mmHg
Not a substitute for medical advice. Blood pressure category informs but does not replace a diagnosis or treatment plan from a qualified healthcare provider.
What is a Blood Pressure?
A Blood Pressure Calculator classifies a systolic and diastolic blood pressure reading according to the 2017 American College of Cardiology / American Heart Association (AHA/ACC) hypertension guideline, sorting your result into Normal, Elevated, Stage 1 Hypertension, Stage 2 Hypertension, or Hypertensive Crisis. It also calculates mean arterial pressure (MAP), a related measure of average arterial pressure often used in clinical and critical care settings.
Blood pressure categories matter because cardiovascular risk rises progressively with each stage, and the 2017 guideline lowered the threshold for Stage 1 Hypertension compared to earlier guidelines, meaning more people now fall into a category warranting attention. This calculator applies those exact published thresholds so you can see immediately where a given reading falls.
How to use this Blood Pressure calculator
- Enter your Systolic Pressure — the top number from your blood pressure reading.
- Enter your Diastolic Pressure — the bottom number from your reading.
- Review the calculated BP Category shown prominently in the results panel.
- Check the Mean Arterial Pressure (MAP) value for additional context.
- If your category is Stage 1 or higher, discuss the result and next steps with a qualified healthcare provider.
- If your reading falls in the Hypertensive Crisis range, seek immediate medical attention rather than relying on this tool alone.
Formula & Methodology
Mean Arterial Pressure (MAP) = Diastolic Pressure + (Systolic Pressure − Diastolic Pressure) ÷ 3 Blood pressure categories follow the 2017 ACC/AHA Hypertension Clinical Practice Guideline: Normal (<120 and <80), Elevated (120-129 and <80), Stage 1 Hypertension (130-139 or 80-89), Stage 2 Hypertension (≥140 or ≥90), and Hypertensive Crisis (>180 and/or >120). Worked example: A reading of 145/92 mmHg falls into Stage 2 Hypertension because the systolic value of 145 exceeds the 140 threshold. Its MAP is 92 + (145 − 92) ÷ 3 = 109.7 mmHg.
Frequently Asked Questions
The 2017 American College of Cardiology / American Heart Association guideline defines five categories: Normal (under 120/80), Elevated (120-129 systolic and under 80 diastolic), Stage 1 Hypertension (130-139 or 80-89), Stage 2 Hypertension (140+ or 90+), and Hypertensive Crisis (over 180 and/or over 120). Each category reflects an increasing level of cardiovascular risk.
Mean arterial pressure is the average pressure in your arteries during one full cardiac cycle, calculated as diastolic pressure plus one-third of the pulse pressure (systolic minus diastolic). MAP is often used in critical care settings because it better reflects the pressure actually perfusing organs than systolic or diastolic pressure alone.
A reading over 180 systolic and/or over 120 diastolic is a hypertensive crisis and requires immediate medical attention, especially if accompanied by symptoms like chest pain, shortness of breath, vision changes, or confusion. Do not wait to see if a repeat reading improves — seek emergency care right away.
No, a single elevated reading can result from stress, caffeine, recent activity, or improper measurement technique, so hypertension is typically diagnosed based on the average of multiple readings taken on separate occasions. Home blood pressure monitoring over several days or ambulatory monitoring is often used to confirm a diagnosis.
Elevated blood pressure (120-129 systolic, under 80 diastolic) is considered a warning zone where lifestyle changes are typically recommended, while Stage 1 Hypertension (130-139 or 80-89) often prompts a conversation about medication, especially if additional cardiovascular risk factors are present. The distinction affects how aggressively a healthcare provider may recommend intervention.
Sit quietly for 5 minutes with your back supported and feet flat on the floor, use a properly sized cuff positioned at heart level, and avoid caffeine, exercise, or smoking for 30 minutes beforehand. Taking two or three readings a minute apart and averaging them gives a more reliable result than a single reading.
The same AHA/ACC categories generally apply across adults, but treatment thresholds and goals can be individualized for older adults based on frailty, other health conditions, and risk of side effects like low blood pressure with standing. Any adjustment to treatment targets should be made by a qualified healthcare provider based on your full health picture.
Reducing sodium intake, maintaining a healthy weight, regular physical activity, limiting alcohol, and managing stress are all evidence-based ways to help lower blood pressure. These changes are often recommended as a first step for Elevated and Stage 1 Hypertension before or alongside medication.
No, this calculator classifies a single blood pressure reading according to the published AHA/ACC categories for informational purposes, but it cannot diagnose hypertension, which requires clinical evaluation and typically multiple readings over time. Only a qualified healthcare provider can make a hypertension diagnosis and recommend treatment.
Hypertension is one of the scored risk factors in the [CHA2DS2-VASc Calculator](/cha2ds2-vasc-calculator/), which estimates stroke risk in people with atrial fibrillation, showing how blood pressure control connects to broader cardiovascular risk assessment. Well-controlled blood pressure is an important part of reducing overall stroke risk regardless of heart rhythm status.
Pulse pressure is the difference between systolic and diastolic pressure and is used internally to calculate mean arterial pressure, though it isn't reported as its own output in this calculator. A persistently wide pulse pressure can be a marker of arterial stiffness and is sometimes discussed alongside [Arterial Age Calculator](/arterial-age-calculator/) results.
The heart spends roughly two-thirds of each cardiac cycle in diastole and one-third in systole at a typical resting heart rate, so weighting diastolic pressure more heavily better approximates the true time-averaged arterial pressure. This is why the standard MAP formula uses diastolic plus one-third of the pulse pressure rather than a simple average.
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