Blood Pressure Calculator

Are you confused with your blood pressure numbers? Not sure when the numbers indicate high blood pressure or low blood pressure?

If you have recently checked your blood pressure and know the top and bottom numbers, we suggest that you key the numbers in the box below and instantly get an idea whether it is normal or abnormal. The calculator compares your blood pressure with that of the normal range for your age group and detects if there is any abnormality. The final result will help you understand why it is important to regularly keep track of your blood pressure readings and gives some tips on how to maintain a normal blood pressure. The American Heart Association (AHA) and other medical organizations recommend that people with high blood pressure or hypertension monitor their blood pressure at home. Home monitoring(1) is easy and saves both time and money and at the same time avoids white coat hypertension(2) Blood pressure is a 'mathematical representation' of two forces.(3) The top number (systolic) is the force applied against the walls of the arteries when the heart beats and the bottom number (diastolic) is the force applied against the walls between the two beats of the heart (i.e. when heart is in a relaxed state). A blood pressure range of 110/70 to 120/80 is considered normal.

Enter Your Details
Sex * Male    Female
Age * (15 - 80 years)
Systolic pressure (Top number) /
Diastolic pressure (Bottom number) *
/ (mm Hg)
Are you taking any blood pressure tablets? * Yes   No
* Required

Note: This calculator is only for people over 15 years of age
The readings should be taken when a person is in a relaxed and resting state. The test should be repeated at different intervals of the day or over a few days until similar values are consistently obtained. Measurement should be avoided immediately after exercise or a meal, as blood pressure may be high at these times.
Beware also of the White Coat Syndrome! It is a condition in which some people blood pressure is high in a doctor’s office but normal at home. This may be because of anxiety and stress. White Coat Syndrome may lead to misdiagnosis and unnecessary treatment.

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Do remember that it is important to measure the blood pressure (BP) properly for the management of hypertension(4) and this may require more than one reading with the right cuff size, its correct positioning on the arm, remaining still and avoiding caffeinated drinks or smoking(5). Both manual or automated blood pressure measurement requires the same precautions.

Monitoring Blood Pressure at Home

High blood pressure or hypertension  is a silent disease and is a major cause of death (6). There maybe no symptoms or very subtle indicators like anxiety, excessive sweating, palpitation, fatigue, dizziness or ringing in the ear. Monitoring the blood pressure at home can prevent the complications such as heart attack and stroke associated with high blood pressure(7).  Home blood pressure devices usually use automatic blood pressure cuff and gauge. Buy one that is authenticated by validated by a reputable medical association. The following instructions can help with the home monitoring of your blood pressure-

  • Preparation for reading – Avoid caffeinated drinks and smoking. Empty your bladder and you should not have done any exercise for at least 30 minutes prior to the reading. Also avoid looking at your cell phones or watch TV during it measurement.(8)
  • Timing of the Reading -Take the reading at the same time everyday – either in morning or evening or at both time.(9)
  • Be still when taking the reading – Take rest for 5 minutes before the reading and be still as moving can affect the reading.(10)
  • Take the right posture by sitting correctly – Sit on a dining chair rather than sofa with your back straight and supported. Keep you feet flat on the floor and not crossed. Your elbow should be supported flat on the table and the cuff should be where your mid- chest is so that it is t the same level as your heart.(11)
  • Bare the Arm for the Reading – Tie the cuff on the bare arm, so either take of the shirt or pull up your sleeves.
  • Choose the right cuff & Tying the cuff-  Depending on your arm size you could choose between small, medium and large cuff. It is best to ask the nurse or doctor what cuff size is best for your arm. The cuff should be tied snugly around your arm and two finger breadths above your elbow.(12)
  • Number of Readings– Take two to three readings at least one to two minutes apart. Use the same arm every day
  • Measure at the same time every day. It’s important to take the readings at the same time each day, such as morning and evening. It is best to take the readings daily for a week and jot it all down in the dairy. Show it to your doctor or nurse on your next visit to the doctor.(13)


  1. Home monitoring confirms clinic diagnosis of high blood pressure - (
  2. Mallion JM. Clinical significance and treatment requirements in white coat and masked hypertension - (
  3. Mathematical Modeling of Noninvasive Blood Pressure Estimation Techniques—Part II - (
  4. Blood pressure chart - (
  5. Measurement of Blood Pressure in Humans - (
  6. Monitoring Your Blood Pressure at Home - (
  7. High Blood Pressure - (
  8. 8 steps to ensure your patients get their BP right - (
  9. Monitoring Your Blood Pressure at Home - (
  10. How to use a blood pressure monitor - (
  11. Home Blood Pressure Monitoring Explained - (
  12. Blood Pressure Monitoring at Home - (
  13. Self-Measurement of Blood Pressure at Home in the Management of Hypertension - (


Ole70, Denmark

What is the source of the equations behind the blood pressure calculator?