Skip to content

Blood Pressure Calculator

Classify a blood-pressure reading and find the mean arterial pressure.

Calculated instantly in your browser.

How is mean arterial pressure calculated from a blood pressure reading?

Mean arterial pressure ≈ diastolic + (systolic − diastolic) ÷ 3, and pulse pressure = systolic − diastolic, with categories following the ACC/AHA 2017 thresholds. Systolic is the pressure when the heart beats; diastolic is between beats. A reading of 120/80 has a MAP of about 93 mmHg and a pulse pressure of 40 mmHg. This tool is informational, not medical advice.

Understanding your result

Systolic is the pressure when the heart beats; diastolic is between beats. MAP estimates the average pressure driving blood to your organs. This tool is informational and not a substitute for medical advice.

Formula and method

Mean arterial pressure ≈ diastolic + (systolic − diastolic) ⁄ 3. Pulse pressure = systolic − diastolic. Categories follow the ACC/AHA 2017 thresholds.

Assumptions and limitations

This tool classifies a single reading and computes derived values for information only; it is not medical advice or a diagnosis. One measurement can be affected by activity, stress, timing and technique, and blood pressure naturally fluctuates. Only a clinician can interpret readings over time and decide what they mean for you.

Worked example

A reading of 120/80 has a MAP of about 93 mmHg and a pulse pressure of 40 mmHg.

How to use this tool

  1. Enter your systolic (top) number.
  2. Enter your diastolic (bottom) number.
  3. Read the category, MAP and pulse pressure.

Common mistakes to avoid

  • Reading too much into a single measurement.
  • Measuring straight after caffeine or exercise.

About the Blood Pressure Calculator

The Blood Pressure Calculator classifies a reading using the ACC/AHA guideline and works out the mean arterial pressure (MAP) and pulse pressure from your systolic and diastolic numbers.

Who should use this tool

Anyone monitoring their blood pressure at home, and students learning the categories.

Benefits

  • Blood-pressure category from the latest guideline.
  • Mean arterial pressure (MAP).
  • Pulse pressure.
  • Instant and private.

Practical use cases

  • Understanding a home reading.
  • Tracking readings over time.
  • Learning the BP categories.

Explore all Health and Nutrition tools

Frequently asked questions

What is a normal blood pressure?

Under the ACC/AHA guideline, normal is below 120/80 mmHg. 120–129 systolic is elevated, and 130/80 or above is hypertension.

What is MAP?

Mean arterial pressure is the average pressure in your arteries over a heartbeat. A range of about 70–100 mmHg is generally considered healthy.

Does one high reading mean I have high blood pressure?

Not necessarily. A single reading can be raised by stress, caffeine, recent activity or measurement technique, and pressure varies through the day. Clinicians usually look at several readings taken over time and in consistent conditions. Discuss any reading that concerns you with a health professional.

Share this tool

Free to use — copy the link, share it anywhere, or add the tool to your own website.

Embed this tool on your site (free)

Copy this code and paste it into any web page — it stays free and always up to date: