Mean Arterial Pressure (MAP) Calculator

1. Enter your systolic pressure. This is the top number on a blood pressure reading, in mmHg.
2. Enter your diastolic pressure. This is the bottom number, in mmHg. It must be lower than the systolic number.
3. Read the result. The tool shows your mean arterial pressure, your pulse pressure, the exact formula, and the ACC/AHA 2017 reference category.

This is an educational estimate. It is not medical advice or a diagnosis.

Mean arterial pressure, or MAP, is the average pressure in your arteries during a single heartbeat. It is not the simple midpoint of the two blood pressure numbers, because the heart spends more of each cycle resting than contracting.

A blood pressure reading has two numbers. The systolic pressure is the higher number, the pressure when the heart beats. The diastolic pressure is the lower number, the pressure when the heart rests between beats. MAP combines them into one figure.

Clinicians use MAP as a single summary of the pressure pushing blood to the organs. It is a derived number, calculated from a reading, so it is only as good as the two values you put in.

A MAP near 70 to 100 mmHg is often cited as a typical adult range, and a MAP of at least about 65 mmHg is commonly referenced as the level needed to perfuse vital organs. These are general reference points, not thresholds for any one person, and MAP alone is never a diagnosis.

The calculator applies the standard published MAP formula. It is the same formula used in clinical references such as StatPearls and MDCalc.

This is mathematically the same as the weighted-average form:

1. Find the pulse pressure. Subtract the diastolic number from the systolic number.
2. Divide by three. Take one third of that pulse pressure.
3. Add the diastolic pressure. Add that third back to the diastolic number to get MAP.

The result is shown to one decimal place in mmHg. The tool also prints the substitution with your own numbers so you can verify it by hand.

Take a common reading of 120 over 80 mmHg, which is a systolic of 120 and a diastolic of 80.

1. Pulse pressure = 120 - 80 = 40 mmHg.
2. One third of the pulse pressure = 40 / 3 = 13.333 mmHg.
3. MAP = 80 + 13.333 = 93.333 mmHg, shown as 93.3 mmHg.

The equivalent form gives the same answer: (120 + 2 x 80) / 3 = 280 / 3 = 93.3 mmHg. This case is loaded as a preset.

MAP for Common Readings

These values come straight from the formula and are reference points, not targets for any one person.

The arithmetic is exact, but the reading you put in, and MAP itself, depend on the person and the moment of measurement.

The Reading You Enter

MAP is only as accurate as the two numbers behind it. A poorly fitted cuff, talking, a full bladder, or crossed legs can all change a reading and therefore the MAP.

Time of Day and Activity

Blood pressure rises and falls through the day and with stress, caffeine, exercise and sleep. A single MAP is a snapshot, not an average of your day.

Age and Arterial Stiffness

With age the large arteries stiffen, which tends to widen the pulse pressure. The same MAP can sit behind very different systolic and diastolic numbers.

Home Monitors

Home and wrist devices vary in accuracy. Using a validated, correctly sized cuff and averaging several readings gives a more reliable MAP than one measurement.

The Formula Itself

The DBP + pulse pressure / 3 formula is an approximation that works best at normal heart rates. At very high heart rates the true mean can differ slightly.

MAP is one summary number. Blood pressure categories are a separate system that classifies the systolic and diastolic numbers themselves. The table below is the 2017 ACC/AHA guideline reference, shown for context, not as a diagnosis.

These categories come from the 2017 ACC/AHA hypertension guideline. They describe the reading, not the MAP, and a category label is not a diagnosis. To read more, see our guide to blood pressure categories explained.

Diet also shapes blood pressure over time. Our guide on sodium and blood pressure covers how salt intake fits in.

Reading a Monitor or Lab Note

Some blood pressure monitors and clinical notes report a MAP. This tool reproduces that figure from the two numbers and shows the formula behind it.

Checking a Calculation

Students, nurses and clinicians can verify a textbook or spreadsheet answer against the published formula, with the worked substitution printed.

Understanding a Reading

Seeing the MAP and the pulse pressure together can help you understand what a reading means, alongside the category table, without treating any of it as a diagnosis.

Alongside Other Measures

Blood pressure sits with other numbers worth tracking, such as body mass index in our BMI calculator and kidney function in our eGFR calculator.

1. Averaging the Two Numbers

MAP is not the plain average of systolic and diastolic. Because the heart rests for most of each cycle, diastole is weighted more heavily, which is why the formula divides the pulse pressure by three.

2. Reading MAP as a Diagnosis

MAP is a derived number, not a diagnosis. A single MAP cannot tell you that you have, or do not have, any condition.

3. Acting on One Reading

Blood pressure moves through the day. One MAP is a snapshot, so base nothing on a single measurement.

4. Swapping the Numbers

Entering the diastolic as the systolic gives a wrong answer. The top number must be the larger one; the tool flags a reversed reading.

5. Trusting an Uncalibrated Device

A poorly fitted or uncalibrated home monitor can be off by several mmHg, which flows straight into the MAP.

6. Changing Medicine Because of the Number

Treatment and dosing decisions belong with a clinician who sees your full history. Do not adjust anything based on this estimate.

The calculator reproduces the standard MAP formula and the ACC/AHA 2017 category cutoffs exactly. The limits lie in what one derived number from one reading can tell one person.

This is not a diagnosis. Discuss any reading or concern with a clinician, who can measure properly and add clinical context.

The standard formula is MAP = DBP + (SBP - DBP) / 3, which is the same as (SBP + 2 x DBP) / 3. SBP is the systolic (top) number and DBP is the diastolic (bottom) number, both in mmHg.

A MAP near 70 to 100 mmHg is often cited as a typical adult range, and at least about 65 mmHg is commonly referenced to perfuse vital organs. These are general reference points, not thresholds for any one person, and MAP alone is not a diagnosis.

No. Because the heart rests for roughly two thirds of each cycle, diastole is weighted more heavily. That is why the formula adds only one third of the pulse pressure to the diastolic number, rather than taking a plain midpoint.

Pulse pressure is the systolic number minus the diastolic number. For a 120/80 reading it is 40 mmHg. The tool shows it as a secondary result alongside the MAP.

A MAP of at least about 65 mmHg is commonly referenced as the level needed to keep blood flowing to vital organs. It is a general reference point used in clinical settings, not a personal target, and the right value depends on the situation and the person.

No. MAP is a derived number, not a diagnosis. The ACC/AHA category shown is a reference label for the reading, not a medical conclusion. Only a clinician can diagnose a blood pressure condition.

Yes. Blood pressure is measured in millimetres of mercury, written mmHg, worldwide, so there is no separate imperial unit to convert.

The systolic pressure, when the heart beats, is always higher than the diastolic pressure, when it rests. If the top number is not larger, the reading was likely entered in the wrong order, so the tool flags it.

No. This is an educational estimate, not medical advice. Do not start, stop or change any medicine because of it. Discuss results with a clinician.

No. The math runs in your browser. The Save button keeps results only in your own browser storage.

• Mean Arterial Pressure (DeMers and Wachs) (StatPearls, NCBI Bookshelf; MAP formula, accessed 2026-10-05).
• 2017 ACC/AHA Guideline for High Blood Pressure in Adults (Whelton et al., Hypertension 2018) (American Heart Association journals; blood pressure categories, accessed 2026-10-05).
• 2017 ACC/AHA high blood pressure guideline (Whelton et al.) (PubMed record; accessed 2026-10-05).
• Mean Arterial Pressure (MAP) (MDCalc; formula cross-reference, accessed 2026-10-05).