Blood Pressure Calculator

Table of contents:

Blood Pressure Calculator

What actually Blood pressure is?

Blood pressure (BP) also referred to as Systolic pressure is the pressure applied to the Blood vessels (arteries, veins, and capillaries) during the circulation of blood around the body. The pressure is due to work done by the heart to pump blood through the circulatory system. Blood pressure is highest in the arteries than capillaries and after that in veins.

Blood pressure is calculated in millimeters of mercury (mmHg). Normal blood pressure is different as men and women are compared.

  • Average adult Blood pressure is round about 120 mmHg (16kPa) systolic with 80 mmHg (11kPa) diastolic commonly abbreviated as 120/80 mmHg.
  • Standard Normal BP of men is 127/79 mmHg
  • Standard Normal BP of women is 122/77 mmHg

Blood pressure is related and a vital sign to indicate respiratory rate, oxygen saturation, heart rate and temperature of the body.

Bloody pressure is affected by total peripheral resistance, cardiac output, emotional state, arterial stiffness and is also changes according to a different situation, activity, and state of disease.

Low Blood pressure is called hypotension and high blood pressure that is high consistently is called hypertension. Sudden and long term duration of both can cause serious diseases. Long term hypertension is responsible for cardiac heart diseases, strokes and kidney failure.

Here is a Blood pressure chart ranging normal, and high BP.


Category Systolic BP, mmHg Diastolic BP, mmHg
Optimal < 120 < 80
Normal 120-129 80-84
High Normal 130-139 85-89
Grade 1 hypertension 140-159 90-99
Grade 2 hypertension 160-179 100-109
Grade 3 hypertension ≥ 180 ≥ 110
Isolated systolic hypertensionb ≥ 140 ≥ 90

Medical Disorders  

There are certain disorders occurs due to high blood pressure and low blood pressure and disorders in blood pressure showing excessive or maladaptive fluctuation.

High Blood Pressure

Arties have thick walls and narrow center. When blood passes and putts high pressure on arteries for a long period of time is called high blood pressure and this eventually increases the risk for Cardiac heart diseases. Narrow arteries and high pressure from heart are the major reasons for High BP.

Symptoms of High Blood pressure:

  • Severe headache.
  • Fatigue
  • Difficulty breathing.
  • Irregular heartbeat.
  • Blood in the urine.
  • Vision problems.
  • Chest pain.
  • Pounding in your chest, neck, or ears.

Causes of High Blood pressure:

  • Smoking tobacco
  • Drugs
  • Being overweight or obese
  • Older age
  • Lacking physical activity
  • Genetics
  • Family history of high blood pressure
  • Chronic kidney disease
  • Adrenal and thyroid disorders
  • Too much alcohol consumption per day
  • Sleep apnea
  • Too much salt in the diet
  • Stress

Certain consequences due to High Blood pressure

There are different consequences of high BP as per situation, medical condition and so on. Here are some of the major problems due to high BP:

  • Heart attack or stroke: High blood pressure can cause atherosclerosis which causes increase stiffness and thickness of arteries which ultimately leads to heart attack, stroke and other problems.
  • Aneurysm: High BP causing weakening of blood vessels and bulging ultimately forming an aneurysm, which can be life-threatening if ruptures.
  • Heart failure: To pump blood into the blood vessels against the pressure the heart has to work more than normal.  This causes left ventricular hypertrophy (thickening of walls of heart’s chambers). This can eventually be causing problems for the heart to pump sufficient blood to every body part which can cause heart failure.
  • Hardening and narrowing of blood vessels in eyes: This can cause loss of vision in a person.
  • The trouble with remembering and understanding:  uncontrolled hypertension can cause a steep decrease inability of a person to remember, think or learn something. This problem is very usual in people having long-term high blood pressure.
  • Dementia: Blocked or narrowing of vessels in the brain can cause vascular dementia due to low blood reaching the brain. This also causes an increase in the risk of strokes and strokes can cause vascular dementia as well.

Low Blood Pressure

Low blood pressure is when the blood pressure in millimeters of mercury drops to 90 mmHg (systolic) and 60 mmHg (diastolic). Low blood pressure is hypotension when your heart pushes blood slower than normal.

Low blood pressure is good in some cases but can be a life threat in some situations as well.

Symptoms of Low Blood pressure

  • Dizziness or lightheadedness
  • Nausea
  • Fatigue
  • Lack of concentration
  • Syncope (Fainting)
  • Blurred vision

Symptoms in Extreme hypotension are:

  • Confusion, especially in older people
  • Weak and rapid pulse
  • Rapid, shallow breathing
  • Cold, clammy, pale skin

Causes of low Blood pressure:

  • Pregnancy: Low blood pressure in pregnancy is normal as the circulatory system expands rapidly during the period and blood pressure drops. After giving birth pressure comes back to normal.
  • Heart problems: Some heart conditions like bradycardia that can lead to low blood pressure include extremely low heart rate, heart valve problems, heart attack, and heart failure.
  • Endocrine problems: low BP is caused by Thyroid conditions like parathyroid disease, Addison’s disease (adrenal insufficiency), hypoglycemia (low blood sugar) and some of the time diabetes can cause low blood pressure to occur.
  • Dehydration: low water intake and more loss of water can cause weakness, dizziness, and fatigue as well. Other aspects like vomiting, severe diarrhea, doing over diuretic and strenuous exercise can ultimately cause dehydration and low BP.
  • Blood loss: losing blood due to injuries, internal bleeding (hemorrhage) and other related situation causes blood amount in body and cause a drop in blood pressure.
  • Severe infection: Infections like septicemia when enters the bloodstream it can cause a life-threatening drop in BP, called septic shock.
  •  Allergic reaction (anaphylaxis): Allergies are common. Anaphylaxis is one common allergy that is caused by foods, specific medications, and insect’s venoms. This allergy can cause itching, breathing problems, hives, swollen throat, and severe drop in Blood pressure.
  • Intake of non-nutritious diet: Having a diet which lacks folate and B-12 which can cause the body to produce low red blood cells which is called anemia. This can lead to life-threatening low blood pressure.

How to calculate Blood Pressure

There is no special blood pressure formula as this is measured by using Sphygmomanometers and then using the readings to calculate mean (average) arterial pressure.

Here are some steps that you can use to measure blood pressure using a sphygmomanometer.

  • At the beginning of the measurement, make sure that you use a proper size of cuff according to the person. The size of the cuff’s bladder should be approximately equal to 80% of the perimeter of the arm (upper).
  • Afterward, wrap up the cuff around the upper arm while keeping the cuff’s lower edge just one inch above the antecubital fossa.
  • Then press the stethoscope’s bell lightly just over the brachial artery and below the cuff’s end.
  • Inflate the cuff with air up to 180 mmHg. Release the air at 3mm/sec from the cuff.
  • Use the stethoscope to listen and at the same time observe the sphygmomanometer. The first Korotkoff (knocking sound) is the patient’s systolic pressure. After that knocking sound when the sound disappears, that is subject’s diastolic pressure e.g. 130/90 mmHg.
  • Observe and record the same with the other arm and note down the difference. You should also record the person’s position (supine) and the size of the cuff i.e. child cuff, standard or adult cuff.
  • If the person’s pressure is raised, measure the Blood Pressure again with the same procedure at least two more times while keeping some time gap between each measurement.

After getting the values you can use our Blood pressure and heart rate calculator to get you the mean arterial pressure (MAP).

Using our blood pressure calculator can help you quickly find out average blood pressure and you can use those values and decide whether you need to see a doctor or use your daily medication instead.

All you need is systolic and diastolic pressure readings and insert them in the provided areas and hit the “calculate” button.

You can manually calculate the MAP by using MAP formula:

MAP = 1/3 * SBP + 2/3 * DBP


MAP= Mean Arterial Pressure

SBP= Systolic Blood pressure

DBP= Diastolic Blood Pressure

Just putting the values in the formula will give you the mean pressure of blood.

You can also use our Heart rate Calculator to check your precise heart rate at different situations.

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