Blood Pressure Calculator
Determines mean arterial pressure and pulse pressure from systolic and diastolic measurements.
You can read more on blood pressure and the stages of hypertension in the text below the tool.
The blood pressure calculator uses the measured values of systolic and diastolic pressure to estimate, based on formulas, the mean arterial pressure (MAP), the blood pressure status (ranging from normal, pre-hypertension to hypertension stage II).
The two measurements are input in millimeters of mercury (mmHg), the first being the maximum pressure in the system while the second one being the pressure obtained in between beats.
The two formulas used are:
■ For mean arterial pressure: MAP ≈ [(2*DP) + SP]/3
■ For pulse pressure: PP = SP – DP
The hypo, normal, hyper -tension interpretation accounts for SP, DP and the following stages:
| Blood Pressure Status | Systolic (mm Hg) | IF | Distolic (mm Hg) | ||
| Min | Max | Min | Max | ||
| Normal Blood Pressure | <120 | and | <80 | ||
| Pre-hypertension | 120 | 139 | or | 80 | 89 |
| Stage I High Blood Pressure (Hypertension) | 140 | 159 | or | 90 | 99 |
| Stage II High Blood Pressure (Hypertension) | 160 | 180 | or | 100 | 110 |
| Hypertensive crisis (where emergency care is required) | >180 | or | >110 | ||
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Steps on how to print your input & results:
1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.
2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.
Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.
Variables considered
Blood pressure is one of the widely measured vital signs (along with heart rate, respiratory rate and temperature) defined as the pressure applied by the circulating blood on the blood vessel surface. It is expressed in mmHg and as a rapport of SP/DP.
Systolic blood pressure is the maximum achievable pressure during heart contraction (heart beat).
Diastolic blood pressure is the minimum of the two values, achievable during the resting period between two subsequent contractions.
BP is controlled by the nervous and endocrine systems. Values lower than normal are classified under the term hypotension while values higher than normal are classified under hypertension.
Blood pressure formulas
The mean arterial pressure is the average blood pressure during one complete cardiac cycle, meaning the pumping of the blood from the ventricle into the arteries during one contraction and the subsequent relaxation period.
MAP ≈ [(2*DP) + SP]/3
The pulse pressure is the difference between the systolic and the diastolic components of the BP. It can be translated into the force generated by each heart contraction. During rest PP is around 40 mmHg.
PP = SP – DP
Blood pressure chart
The following introduces two ways in which the blood pressure values can be interpreted (based on the same intervals), in order to provide the patient with a cardiovascular status:
A) Blood pressure status table
| Blood Pressure Status | Systolic (mm Hg) | IF | Distolic (mm Hg) | ||
| Min | Max | Min | Max | ||
| Normal Blood Pressure | <120 | and | <80 | ||
| Pre-hypertension | 120 | 139 | or | 80 | 89 |
| Stage I High Blood Pressure (Hypertension) | 140 | 159 | or | 90 | 99 |
| Stage II High Blood Pressure (Hypertension) | 160 | 180 | or | 100 | 110 |
| Hypertensive crisis (where emergency care is required) | >180 | or | >110 | ||
B) Blood pressure chart
| 110 | Hypertension | ||||||||||
| 100 | |||||||||||
| 90 | Hypertension | Stage II | |||||||||
| 80 | pre-Hypertension | Stage I | |||||||||
| 70 | Normal blood pressure | ||||||||||
| 60 | |||||||||||
| 50 | |||||||||||
| 40 | |||||||||||
| 70 | 80 | 90 | 100 | 110 | 120 | 130 | 140 | 150 | 160 | 170 | |
References
1. Hall J. (2015) Guyton and Hall Textbook of Medical Physiology 13th ed. Elsevier Health Sciences.
2. Klabunde R. (2005) Cardiovascular Physiology Concepts. Lippincott Williams & Wilkins.
3. Caro CG. (1978) The Mechanics of The Circulation. Oxford [Oxfordshire]: Oxford University Press.
Specialty: Cardiology
System: Cardiovascular
Objective: Determination
Type: Calculator
No. Of Variables: 2
Abbreviation: BP
Article By: Denise Nedea
Published On: March 15, 2017 · 04:58 AM
Last Checked: March 15, 2017
Next Review: March 9, 2023