This blood pressure calculator estimates your mean arterial pressure based on your values of systolic and diastolic pressures. You can read more about these determinations below the form.
How does this blood pressure calculator work?
This heart function tool can help you determine your blood pressure constants which are the mean arterial pressure (MAP) and pulse pressure (PP), the measures of the perfusion pressure of the heart. You are asked to input the values of the systolic (SP) and diastolic pressure (DP) that are measured in mmHg. You will also receive the status of your blood pressure according to this reading.
The mean arterial pressure (MAP) formula used by the blood pressure calculator is:
MAP ≈ [(2*DP) + SP]/3
The pulse pressure (PP) formula used is:
PP = SP – DP
The calculator returns the blood pressure status reading based on the following ranges for SP and DP:
| 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 | ||
Example calculation
Here are some cases and their corresponding results:
| No | Systolic pressure (mmHg) | Diastolic pressure (mmHg) | Result |
| 1 | 115 | 70 | Mean Arterial Pressure: 85mmHg |
| Blood Pressure status: Normal pressure | |||
| Pulse Pressure (PP): 45mmHg | |||
| 2 | 127 | 85 | Mean Arterial Pressure: 99mmHg |
| Blood Pressure status: Pre-hypertension | |||
| Pulse Pressure (PP): 42mmHg | |||
| 3 | 145 | 93 | Mean Arterial Pressure: 110mmHg |
| Blood Pressure status: Hypertension Stage I | |||
| Pulse Pressure (PP): 52mmHg | |||
| 4 | 170 | 104 | Mean Arterial Pressure: 126mmHg |
| Blood Pressure status: Hypertension Stage II | |||
| Pulse Pressure (PP): 66mmHg |
What is blood pressure?
It is one of the vital signs and represents the pressure of the circulating blood on the surface of the blood vessels. It is expressed through the rapport of systolic pressure over diastolic pressure and is measured in millimeters of mercury (mmHg). The first one represents the maximum pressure while beating and the second one is the pressure between beats. BP is under the control of the nervous and endocrine systems and varies with age, activity and health status. Low blood pressure is known as hypotension while pathologically high values are defined as hypertension.
Defining MAP (mean arterial pressure):This value describes the average blood pressure of a person during a single cardiac cycle when blood is pumped from the ventricle into the arteries.
Defining PP (pulse pressure): This describes the difference between the systolic and diastolic pressures and could be translated as the force generated by each of the heart contractions. In the case of resting blood pressure PP is around 40mmHg.
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) Caro CG. (1978) The Mechanics of The Circulation. Oxford [Oxfordshire]: Oxford University Press.
3) Klabunde R. (2005) Cardiovascular Physiology Concepts. Lippincott Williams & Wilkins.
19 Jan, 2015