Enter a blood pressure reading to see its category under the 2017 ACC/AHA guideline, along with the mean arterial pressure and pulse pressure. Free, private, and runs entirely in your browser.
The category depends on the higher of your systolic and diastolic categories. Mean arterial pressure estimates the average pressure during a heartbeat as one third systolic plus two thirds diastolic, and pulse pressure is the difference between the two numbers.
What is normal blood pressure? Under 120 systolic and under 80 diastolic. Elevated is 120 to 129 with diastolic under 80, stage 1 is 130 to 139 or 80 to 89, and stage 2 is 140 or 90 and above.
What is MAP? Mean arterial pressure is the average pressure in the arteries during one heartbeat. A MAP of about 70 to 100 mmHg is generally considered adequate.
A reading of 118 over 76 is normal. MAP = (118 + 2 × 76) ÷ 3 = 90 mmHg and pulse pressure = 118 − 76 = 42 mmHg. A reading of 135 over 85 is stage 1 hypertension, with MAP 101.7 mmHg.
When is blood pressure an emergency? A reading above 180 systolic and/or 120 diastolic with symptoms such as chest pain, shortness of breath, weakness or trouble speaking needs emergency care.
What if only one number is high? The category is set by the higher of the two, so a high systolic or a high diastolic alone is enough.
Blood pressure was first measured directly in 1733 by Stephen Hales, who connected a tube to an artery of a horse. Scipione Riva-Rocci invented the cuff-based sphygmomanometer in 1896, and Nikolai Korotkoff described the sounds used to read systolic and diastolic pressure in 1905. The 2017 ACC/AHA guideline lowered the threshold for stage 1 hypertension to 130 over 80.
Use this calculator to understand a home or clinic reading and to log your results for your doctor. This is general information, not medical advice. Talk to a doctor or other qualified professional about your own results.
How often should I check my blood pressure? Your clinician will advise. People with high readings or on treatment often check at home regularly.
Is a low reading a problem? Not always, but low readings with dizziness or fainting should be discussed with a clinician.