How do I measure blood pressure correctly?

Sit quietly for 5 minutes before measuring. Sit with back supported, feet flat on floor, arm at heart level. Place cuff 1–2 cm above elbow crease. Do not cross legs. Do not talk during measurement. Take two readings, 1 minute apart, and average them. Measure at the same time of day for consistent monitoring.

What causes high blood pressure?

Primary (essential) hypertension (90–95% of cases): no single cause — combination of genetics, high salt intake, obesity, physical inactivity, excess alcohol, smoking, and chronic stress. Secondary hypertension (5–10%): caused by kidney disease, thyroid disorders, sleep apnoea, or certain medications.

What blood pressure level requires medication?

Stage 2 hypertension (≥140/90) almost always requires medication alongside lifestyle changes. Stage 1 (130–139/80–89): medication if 10-year cardiovascular risk is ≥10%, or if diabetes, CKD, or existing heart disease is present. Lifestyle modification alone (diet, exercise, salt reduction) can reduce systolic BP by 5–15 mmHg.

How can I lower blood pressure naturally?

Evidence-based methods: DASH diet (rich in fruits, vegetables, whole grains, low-fat dairy) reduces systolic by 8–14 mmHg. Reduce sodium to <2,300mg/day (ideally <1,500mg). Aerobic exercise 30 min/day, 5 days/week reduces BP by 4–9 mmHg. Limit alcohol to <1 drink/day (women) or <2/day (men). Lose weight — each kg lost reduces BP by ~1 mmHg.

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Blood Pressure Calculator

120

Diastolic Pressure (mmHg) — bottom number

Age (years)

Pulse Pressure

Mean Arterial Pressure

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What do blood pressure numbers mean?
Blood pressure is expressed as systolic/diastolic mmHg. Normal: below 120/80 mmHg. Elevated: 120–129/<80. Hypertension Stage 1: 130–139/80–89. Hypertension Stage 2: 140+/90+. Hypertensive crisis: above 180/120 — seek emergency care immediately. For South Asians, cardiovascular risk increases at lower thresholds than Western populations. This tool is for screening only — consult a doctor for diagnosis.

Medically reviewed by Dr. P Nair, MBBS, MD (Community Medicine) · Author: Mayra

✓ Last reviewed: June 2026 · Methodology

Blood pressure measures the force of blood against artery walls. The upper number (systolic) is pressure during heartbeats; the lower (diastolic) is pressure between beats. Normal: below 120/80 mmHg. Stage 1 hypertension: 130–139/80–89. Stage 2: ≥140/90. A hypertensive crisis above 180/120 requires immediate medical attention.

Understand your blood pressure reading and health category

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📜 AHA/ACC & WHO source for BP categories

Categories follow the AHA/ACC 2017 guideline (normal <120/80; elevated 120–129/<80; stage 1: 130–139 or 80–89; stage 2: ≥140 or ≥90) cross-referenced with WHO hypertension guidance. A single reading is not a diagnosis — confirm with repeated measurements and a clinician. Last reviewed: June 2026.

📊 Methodology: This calculator uses validated clinical formulas as cited in the sources below. Results are estimates for general informational purposes. Consult a qualified healthcare professional before making health decisions.

Last updated: June 2026

How to read a blood pressure measurement

Blood pressure is measured in millimetres of mercury (mmHg) and recorded as two numbers: systolic pressure over diastolic pressure (e.g. 120/80 mmHg). The systolic number (top) measures the pressure in your arteries when your heart beats. The diastolic number (bottom) measures the pressure between beats when your heart rests. Related: use the Heart Rate Zone Calculator to go further, or the BMI Calculator for a different angle.

Blood pressure categories (AHA/ACC 2017 guidelines)

Category	Systolic (mmHg)	Diastolic (mmHg)
Normal	Less than 120	Less than 80
Elevated	120–129	Less than 80
Stage 1 Hypertension	130–139	80–89
Stage 2 Hypertension	140 or higher	90 or higher
Hypertensive Crisis	Higher than 180	Higher than 120

Pulse pressure and mean arterial pressure

Pulse Pressure = Systolic − Diastolic. Normal range: 30–50 mmHg. A pulse pressure above 60 mmHg in adults over 50 is associated with increased cardiovascular risk.

Mean Arterial Pressure (MAP) = Diastolic + (Pulse Pressure / 3). Normal range: 70–100 mmHg. MAP represents the average pressure throughout the cardiac cycle and is a better indicator of tissue perfusion than systolic alone.

How to lower blood pressure naturally

DASH diet: Reducing sodium to under 2,300 mg/day can lower BP by 5–6 mmHg. The DASH diet (Dietary Approaches to Stop Hypertension) rich in fruits, vegetables, whole grains, and low-fat dairy can reduce BP by 8–14 mmHg
Exercise: 150 minutes/week of moderate aerobic exercise (brisk walking, cycling, swimming) reduces BP by 5–8 mmHg
Weight loss: Losing 5 kg reduces systolic BP by approximately 5 mmHg
Limit alcohol: Reducing alcohol to ≤1 drink/day for women, ≤2 for men lowers BP by 3–5 mmHg
Quit smoking: Each cigarette temporarily raises BP by 5–10 mmHg; long-term smoking causes arterial stiffening

What is normal blood pressure by age?

Age Group	Normal (Systolic/Diastolic)	High (Hypertension Stage 1)	Low
Under 18	Below 120/80 mmHg	130/80+ mmHg	Below 90/60 mmHg
18–39	Below 120/80 mmHg	130/80+ mmHg	Below 90/60 mmHg
40–59	Below 120/80 mmHg	130/80+ mmHg	Below 90/60 mmHg
60+	Below 130/80 mmHg	140/90+ mmHg	Below 90/60 mmHg

Source: WHO/ISH 2020 Hypertension Guidelines; American Heart Association 2023.

Health disclaimer: This calculator provides estimates for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Results are based on population averages and may not apply to individuals with specific health conditions. Always consult a qualified healthcare professional. Reviewed by Dr. P Nair, MBBS, MD.

Frequently asked questions about blood pressure

When is the best time to measure blood pressure? BP varies throughout the day — lowest during sleep, highest in early morning. For consistent readings: measure in the morning before medication and breakfast, sit quietly for 5 minutes, use the same arm each time, avoid coffee/exercise for 30 minutes before. Take 2–3 readings 1 minute apart and average them.

What is white coat hypertension? White coat hypertension is elevated blood pressure measured in a clinical setting that is normal when measured at home. It affects approximately 15–30% of people diagnosed with hypertension. Home blood pressure monitoring is now recommended alongside clinic measurements to distinguish true hypertension from white coat effect.

Is 130/80 high blood pressure? Under the 2017 AHA/ACC guidelines, 130/80 mmHg is classified as Stage 1 hypertension. Earlier guidelines (JNC 7) used 140/90 as the threshold. The lower threshold was adopted to encourage earlier lifestyle intervention before BP escalates further.

Sources & References

AHA/ACC — 2017 Hypertension Guidelines — Stage definitions: normal <120/80; stage 1 130–139/80–89; stage 2 ≥140/90
WHO — Hypertension Fact Sheet — Global hypertension prevalence and threshold criteria

How to measure blood pressure correctly — 5-step guide

Blood pressure readings vary by up to 10–15 mmHg depending on measurement technique. Following proper protocol produces reliable readings that reflect true cardiovascular status:

Rest for 5 minutes beforehand. Sit quietly with feet flat on the floor and back supported. Avoid caffeine, exercise, and smoking for 30 minutes before measuring.
Position your arm at heart level. Rest your arm on a table so the cuff is at the same height as your heart. Cuffs held below or above heart level produce inaccurate readings.
Apply the cuff correctly. Place the cuff 1–2 cm above the bend of the elbow (antecubital fossa). The cuff should be snug but allow one finger underneath. Use the correct cuff size — too small reads high; too large reads low.
Do not talk or cross your legs during measurement. Talking raises systolic by 6–7 mmHg. Crossing legs raises systolic by 2–8 mmHg.
Take two readings, 1–2 minutes apart, and average them. First readings are often higher due to white-coat effect. Measure at the same time each day for monitoring trends.

Technique Error	Effect on Reading
Talking during measurement	Systolic +6–7 mmHg
Cuff over clothing	Systolic +10–50 mmHg
Arm below heart level	Systolic +8 mmHg
Crossed legs	Systolic +2–8 mmHg
Full bladder	Systolic +10–15 mmHg
Wrong cuff size (too small)	Systolic +10–15 mmHg

When does blood pressure require medication?

The decision to start antihypertensive medication depends on blood pressure level, cardiovascular risk factors, and presence of target organ damage. Use this as a guide — your doctor makes the final call:

BP Category	Systolic / Diastolic	Medication Decision	First-line Treatment
Normal	<120 / <80	No medication needed	Maintain healthy lifestyle
Elevated	120–129 / <80	No medication	Lifestyle changes for 3–6 months
Stage 1 Hypertension	130–139 / 80–89	If 10-yr CVD risk ≥10%, or diabetes/CKD present	Lifestyle + consider ACE inhibitor or ARB
Stage 2 Hypertension	≥140 / ≥90	Almost always requires medication	Lifestyle + 1–2 medications (ACE inhibitor/ARB + calcium channel blocker)
Hypertensive Crisis	>180 / >120	Emergency treatment required	Immediate medical attention

Source: AHA/ACC 2017 Hypertension Guidelines; Indian Hypertension Guidelines 2023 (API).

DASH diet and lifestyle interventions: how much can they lower BP?

Lifestyle modifications can reduce systolic blood pressure by 5–15 mmHg — significant enough to eliminate the need for medication in Stage 1 hypertension, or reduce medication doses in higher stages:

Intervention	Systolic BP Reduction	Evidence Quality
DASH diet (fruits, vegetables, low-fat dairy, reduced sodium)	8–14 mmHg	Strong (multiple RCTs)
Sodium reduction to <2,300 mg/day	5–6 mmHg	Strong
Weight loss (per kg lost)	~1 mmHg per kg	Strong
Aerobic exercise (150 min/week)	4–9 mmHg	Strong
Limiting alcohol (<2 drinks/day men, <1 women)	3–4 mmHg	Moderate-Strong
Stopping smoking	Indirect (reduces CVD risk)	Strong
Stress management / meditation	3–5 mmHg	Moderate

Sources: NEJM DASH Diet trial; AHA Scientific Statement on Lifestyle Management of Hypertension; WHO HEARTS technical package.

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⚕️ Medical disclaimer: This calculator provides educational estimates only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. Formulas and reference ranges follow WHO and ICMR published guidelines — see our methodology.