How is blood pressure classified in this calculator?

This blood pressure calculator uses widely adopted adult guidelines. Normal: systolic < 120 mmHg and diastolic < 80 mmHg. Elevated: systolic 120–129 and diastolic < 80. Stage 1 hypertension: systolic 130–139 or diastolic 80–89. Stage 2 hypertension: systolic ≥ 140 or diastolic ≥ 90. Hypertensive crisis: systolic ≥ 180 or diastolic ≥ 120. Always confirm readings with a clinician.

Can this blood pressure calculator diagnose hypertension?

No. The calculator is for education only and cannot diagnose or treat any condition. A diagnosis of hypertension requires multiple properly taken readings, usually on different days, interpreted by a qualified health professional.

How many readings should I enter?

You can enter one reading or up to three recent readings. The calculator will show each reading's category and the average. For medical decisions, clinicians often rely on multiple readings over time, including home or ambulatory monitoring.

Does age change the blood pressure categories?

For most adults, the same thresholds are used regardless of age. However, treatment targets and how aggressively blood pressure is managed may differ based on age, overall health, and other conditions. Always follow your clinician's personalized advice.

What should I do if the calculator shows a hypertensive crisis?

If your systolic is 180 mmHg or higher, or your diastolic is 120 mmHg or higher, this can be a medical emergency—especially if you have chest pain, shortness of breath, confusion, vision changes, or severe headache. Do not rely on this tool. Seek urgent medical care or emergency services immediately.

Blood Pressure Calculator

Classify your blood pressure, see your average, and get guideline-based lifestyle tips. For adults only – not a diagnosis.

Emergency disclaimer: If your systolic is ≥ 180 or diastolic ≥ 120 mmHg, or you feel unwell (chest pain, shortness of breath, confusion, vision changes, severe headache), seek urgent medical care immediately.

Age (years)

This tool is intended for adults (18+).

Sex (optional)

Enter your blood pressure readings

Units: mmHg

You can enter 1–3 recent readings (e.g., from different days). The calculator will classify each and show your average.

Reading 1 – Systolic

Reading 1 – Diastolic

Heart rate (optional)

Results

How to measure blood pressure correctly

Sit quietly for at least 5 minutes before measuring.
Empty your bladder and avoid caffeine, smoking, or exercise for 30 minutes beforehand.
Sit with your back supported, feet flat on the floor, and arm supported at heart level.
Use the correct cuff size on bare skin, not over clothing.
Take at least two readings 1–2 minutes apart and record all values.

Understanding your blood pressure result

Blood pressure (BP) is the force of blood pushing against the walls of your arteries. It is written as systolic / diastolic, for example 120/80 mmHg.

This calculator uses widely adopted adult guidelines to classify your readings and highlight when you may need medical review. It is for information only and cannot diagnose or treat any condition.

Blood pressure categories (adults)

Category	Systolic (mmHg)	Diastolic (mmHg)
Normal	< 120	< 80
Elevated	120–129	< 80
Stage 1 hypertension	130–139	or 80–89
Stage 2 hypertension	≥ 140	or ≥ 90
Hypertensive crisis (emergency)	≥ 180	and/or ≥ 120

What do systolic and diastolic mean?

Systolic (top number): pressure when your heart contracts and pumps blood out.
Diastolic (bottom number): pressure when your heart relaxes between beats.

Both numbers matter. In general, the higher category of either systolic or diastolic determines your overall classification.

Why multiple readings matter

Blood pressure naturally varies from moment to moment. A single high reading can be caused by stress, pain, caffeine, or “white coat” effect in a clinic. That’s why:

Clinicians usually confirm high BP with repeated measurements on different days.
Home or ambulatory (24‑hour) monitoring is often used to confirm a diagnosis.
This calculator lets you enter up to three readings and shows the average.

How this blood pressure calculator works

The calculator:

Validates that systolic and diastolic values are within a reasonable adult range.
Classifies each reading into a category using the table above.
Computes the average systolic and diastolic across all valid readings.
Assigns an overall category based on the highest risk reading or average.
Displays tailored risk guidance and lifestyle suggestions.

Average blood pressure

If you enter \( n \) valid readings with systolic values \( S_1, S_2, \dots, S_n \) and diastolic values \( D_1, D_2, \dots, D_n \), the calculator computes:

\( \text{Average systolic} = \dfrac{S_1 + S_2 + \dots + S_n}{n} \)
\( \text{Average diastolic} = \dfrac{D_1 + D_2 + \dots + D_n}{n} \)

Limitations

Designed for adults (18+). Children and teenagers use different charts and percentiles.
Does not account for pregnancy, kidney disease, diabetes, or other specific conditions.
Cannot adjust for medications you may already be taking.
Cannot replace a physical examination or professional judgment.

Evidence‑based lifestyle changes that help blood pressure

For most people, the following changes can help lower blood pressure and reduce cardiovascular risk. Always discuss major changes with your clinician, especially if you take medication.

Reduce salt (sodium) intake – limit processed foods, canned soups, and salty snacks.
Eat more plants – vegetables, fruits, whole grains, nuts, and legumes.
Maintain a healthy weight – even modest weight loss can lower BP.
Be active most days – aim for at least 150 minutes of moderate exercise per week if safe for you.
Limit alcohol – or avoid it altogether.
Stop smoking – tobacco damages blood vessels and raises cardiovascular risk.
Manage stress – through sleep, relaxation techniques, and social support.

When to seek urgent medical help

Call emergency services or go to an emergency department immediately if:

Your systolic is 180 mmHg or higher, or diastolic is 120 mmHg or higher, and you have symptoms such as:
Chest pain, shortness of breath, severe headache, confusion, weakness, or vision changes.
You feel seriously unwell and are worried, regardless of the numbers.

Do not rely on this calculator in an emergency.

Medical disclaimer

This blood pressure calculator is for general information and education only. It does not provide medical advice, diagnosis, or treatment, and must not be used as a substitute for consultation with a qualified health professional who can interpret your readings in the context of your full medical history.

Frequently asked questions

How often should I check my blood pressure?

It depends on your situation. People with well‑controlled blood pressure may only need checks a few times per year, while those with high readings or medication changes may need more frequent monitoring. Your doctor or nurse can advise how often is right for you.

Is home blood pressure monitoring accurate?

Home monitors can be accurate if they are validated, properly maintained, and used with the correct cuff size and technique. Bring your device to your clinic appointment occasionally so it can be compared with a professional device.

Can I lower my blood pressure without medication?

Many people can significantly improve their blood pressure with lifestyle changes such as diet, weight loss, exercise, and reducing alcohol and salt. However, some people will still need medication. Never stop or change prescribed medicines without speaking to your clinician.