Blood Pressure Calculator
Type in the two numbers from your blood pressure reading and this calculator tells you which category they fall into under the American (AHA/ACC) or European (ESC) guideline. It also works out your mean arterial pressure (MAP), which is the average pressure in your arteries across one heartbeat, and your pulse pressure, which is the gap between your top and bottom numbers.
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Guideline
This calculator is for adults. Children's blood pressure is judged against age, sex and height charts, so ask your child's doctor instead.
How each guideline categorises your reading
All values in mmHg. The classifier picks the higher of the two numbers when they fall in different categories.
AHA/ACC 2025 (United States)
| Category | Systolic | Diastolic |
|---|---|---|
| Normal | < 120 | and < 80 |
| Elevated | 120–129 | and < 80 |
| Stage 1 | 130–139 | or 80–89 |
| Stage 2 | ≥ 140 | or ≥ 90 |
| Severe hypertension | > 180 | and/or > 120 |
The 2025 AHA/ACC guideline kept the same four categories and the same 130/80 threshold as the 2017 version. The American Heart Association's 2025 chart calls a reading higher than 180 and/or higher than 120 severe hypertension, or a hypertensive emergency if you also have symptoms. For an average of home readings, the guideline moves the stage 2 line down to 135/85, and the calculator uses that line when you average readings taken at home.
ESC 2024 (Europe)
| Category | Systolic | Diastolic |
|---|---|---|
| Non-elevated | < 120 | and < 70 |
| Elevated | 120–139 | or 70–89 |
| Hypertension | ≥ 140 | or ≥ 90 |
| Severe hypertension | ≥ 180 | or ≥ 110 |
The 2024 ESC guideline uses the first three groups. It calls the lowest one non-elevated, because the risk of heart and blood vessel disease starts to rise even below 120/70, and it recommends checking for a hypertensive emergency at 180/110 or higher, which the calculator shows as severe hypertension. For an average of home readings, its lines are 120/70 for elevated and 135/85 for hypertension, and the calculator uses those when you average readings taken at home. The European Society of Hypertension's 2023 guideline still uses the older scheme of optimal, normal, high-normal and grades 1 to 3, which both societies shared in 2018.
How to calculate mean arterial pressure (MAP)
To calculate your MAP, take your diastolic (bottom) number and add one third of the gap between your two numbers. For a reading of 120/80 that is 80 + 40 ÷ 3, which comes to about 93 mmHg. Some sources write the same formula as (systolic + 2 × diastolic) ÷ 3, and both give the same answer. The calculator above does this for you.
MAP is the average pressure in your arteries over one whole heartbeat, while your heart squeezes and while it relaxes. That definition and the formula come from StatPearls, a peer-reviewed medical reference hosted by the US National Library of Medicine.
Both the US and European guidelines sort readings by the top and bottom numbers, so for most people at home the category is the result to watch. A reading in the US normal range, from 90/60 up to 119/79, gives a MAP between 70 and about 92 mmHg. The NHS and the US National Heart, Lung, and Blood Institute treat a reading below 90/60 as low blood pressure.
Hospital teams watch MAP closely in very unwell patients. The Surviving Sepsis Campaign guideline, for example, sets 65 mmHg as the starting MAP target for adults in septic shock who need medicines to raise their blood pressure.
How to calculate pulse pressure
Pulse pressure is your top number minus your bottom number, so a reading of 130/80 has a pulse pressure of 50 mmHg. In a healthy young adult it is usually about 40 mmHg, according to StatPearls, which describes a pulse pressure below a quarter of the top number as unusually narrow.
The gap tends to widen from middle age, because the top number keeps rising while the bottom number levels off or falls. The 2024 ESC guideline links this to the main artery stiffening with age, and the 2018 European guideline listed a pulse pressure of 60 mmHg or more in older people as a sign of stiff arteries. If a very wide or very narrow gap keeps showing up in your readings, mention it to your doctor.
Why the calculator shows all three numbers
Two readings can share the same MAP and still mean different things. 116/74 and 140/62 both give a MAP of 88 mmHg. Under the US guideline the first is normal, while the second is stage 2 high blood pressure because its top number is 140. The second also has a pulse pressure of 78 mmHg, well above the 60 mmHg line the 2018 European guideline used for stiff arteries in older people. Under the 2024 European guideline, the first reading counts as elevated, because its bottom number is above 70. MAP on its own hides all of this, which is why the calculator shows the category, MAP and pulse pressure together.
When to take these to your clinician
One reading is just a snapshot. To get a meaningful trend, measure twice daily for one to two weeks (morning before medication, evening before bed) and take the averages to your appointment. The calculator above can average up to 14 readings for you, and Cardilog can do this automatically and export a doctor-ready PDF. If there is no appointment on the horizon, you can talk your numbers through with a cardiologist over video. Read more about understanding blood pressure readings or browse the full blood pressure chart.
When to seek medical care now
Call emergency services or go to the nearest emergency room if your reading is above 180/120 mmHg AND you have any of these symptoms:
- Chest pain or pressure
- Shortness of breath
- Back pain
- Sudden weakness, numbness, or trouble speaking
- Vision changes
- Severe headache or confusion
If your reading is above 180/120 and you have no symptoms, wait at least a minute and measure again. If it is still that high, contact your doctor as soon as possible. The American Heart Association calls this severe hypertension, and a hypertensive emergency when symptoms come with it. The 2024 ESC guideline recommends checking for a hypertensive emergency from 180/110, so the calculator's European option shows its warning from that level.
Frequently Asked Questions
What does a blood pressure calculator do?
A blood pressure calculator takes the top (systolic) and bottom (diastolic) numbers from your reading and tells you which category they fall into. Under the US AHA/ACC 2025 guideline the categories are normal, elevated, stage 1 and stage 2, and the American Heart Association chart adds severe hypertension above 180/120. Under the European ESC 2024 guideline they are non-elevated, elevated and hypertension. This calculator also works out your pulse pressure and mean arterial pressure (MAP), and it can average up to 14 readings.
What's the difference between AHA and ESC blood pressure guidelines?
The American Heart Association and American College of Cardiology (AHA/ACC 2025) call blood pressure high from 130/80 mmHg and split it into two stages. The European Society of Cardiology (ESC 2024) calls it high from 140/90 mmHg and calls anything from 120/70 up to that point "elevated". The US line is lower, so it flags risk earlier. Your doctor will tell you which one they use.
Is 135/85 considered high blood pressure?
The US guideline counts it as high: AHA/ACC 2025 puts 135/85 mmHg in stage 1 hypertension. The 2024 European guideline calls it elevated, one step below its hypertension line of 140/90. If 135/85 is the average of a week of home readings, both guidelines count it as high blood pressure, because home readings run a little lower and 135/85 at home matches 140/90 at a clinic. Either way it is higher than ideal and worth tracking. A single reading is not a diagnosis, so measure twice a day for one to two weeks and talk the trend through with your doctor.
Is 140 over 70 a good blood pressure?
Under the US guideline, 140/70 is stage 2 high blood pressure because the top number is 140. Under the 2024 European guideline, a top number of 140 also counts as hypertension. Its MAP is about 93 mmHg, the same as 120/80, which is why MAP alone can mislead. One reading is not a diagnosis, so measure again over a few days and talk to your doctor if it stays there.
What is mean arterial pressure (MAP)?
Mean arterial pressure is the average pressure in your arteries over one whole heartbeat. The usual estimate is your bottom number plus a third of the gap between your two numbers. A reading in the US normal range, from 90/60 up to 119/79, gives a MAP between 70 and about 92 mmHg. Hospital teams watch MAP closely in very unwell patients. At home, both the US and European guidelines judge your blood pressure by its two numbers, so the category matters more.
What is the MAP for a blood pressure of 120/80?
A reading of 120/80 gives a MAP of about 93 mmHg. Take the bottom number, 80, and add a third of the 40-point gap between the two numbers.
Is a MAP of 110 too high?
A MAP of 110 points to high blood pressure. With the standard formula it only comes from readings where the top number is 140 or more or the bottom number is 90 or more, such as 150/90, and both the US and European guidelines call those readings high. One reading is not a diagnosis, so measure again on a few different days and take the numbers to your doctor.
What is pulse pressure and why does it matter?
Pulse pressure is your top number minus your bottom number, so 130/80 gives 50 mmHg. StatPearls puts a healthy young adult at about 40 mmHg. The gap tends to widen with age as the arteries stiffen, and the 2018 European guideline treated 60 mmHg or more in older people as a sign of stiff arteries. It adds context that the two numbers alone do not give you.
Related Guides
Medical Disclaimer: This calculator is for informational purposes only and is not a substitute for professional medical advice. It sorts readings into categories and can't diagnose high blood pressure, which your doctor diagnoses from several readings taken on different days, often with home monitoring or a 24-hour monitor. Categories are based on the 2025 American Heart Association and American College of Cardiology (AHA/ACC) guideline and the 2024 European Society of Cardiology (ESC) guideline. Always consult a qualified healthcare provider about your personal health situation.