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Blood Pressure Calculator

AHA 2017 guidelines · MAP & Pulse Pressure · ISH/IDH detection · BP tracker & cardiovascular risk analysis

Blood Pressure Reading
For informational purposes only. Consult a healthcare provider for diagnosis and treatment.
Blood Pressure Category
Normal
120/80 mmHg
Systolic Position
▼
Low<90NormalElevatedStage 1Stage 2Crisis
MAP = (Sys + 2×Dia) ÷ 3 PP = Sys − Dia
Systolic
120 mmHg
Diastolic
80 mmHg
MAP
93 mmHg
Pulse Pressure
40 mmHg
Category
Normal
Risk Level
Low
BP Position Map
All-time Average
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Total Readings
0
Trend
→ Stable
Highest
—
Lowest
—
Std Deviation
—
Systolic & Diastolic Trend
Systolic Diastolic 120/80 target 130 HTN
Reading Log
Date & Time Reading Pulse Category Notes
No readings logged yet.
Risk Factor Inputs

Uses your current BP reading plus additional risk factors for a simplified 10-year cardiovascular risk estimate.

This is a simplified risk estimate for educational purposes. For clinical risk scoring, use the ACC/AHA Pooled Cohort Equations or consult your physician.
Estimated 10-Year CVD Risk
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What-If Scenarios
If you lower systolic by 10 mmHg
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If you quit smoking
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Potential BP Reduction from Lifestyle Changes
Personalized Recommendations

How to Use This Calculator

1

Enter Your Reading

Input systolic (top) and diastolic (bottom) numbers. Use Average 3 Readings mode for clinical accuracy.

2

Read the Gauge

The visual BP gauge shows where your systolic reading falls across all 6 AHA categories at a glance.

3

Log & Track

Click "Log Reading" to save. Visit BP Tracker to see trends, morning vs evening patterns, and statistics.

4

Assess Risk

Use Risk Analysis to estimate 10-year cardiovascular risk and see what-if scenarios for lifestyle changes.

Formulas & Methodology

Mean Arterial Pressure (MAP)

MAP = DBP + 1/3 (SBP - DBP)

Average arterial pressure during one cardiac cycle. Normal is 70-100 mmHg. Below 60 risks organ underperfusion.

Pulse Pressure

PP = SBP - DBP

Difference between systolic and diastolic. Normal is 40-60 mmHg. Wide (>60) = arterial stiffness; narrow (<25) = low cardiac output.

AHA 2017 Classification

Normal <120/80 | Elevated 120-129/<80 | Stage 1 130-139/80-89 | Stage 2 ≥140/≥90

Classification uses the higher category when systolic and diastolic fall into different categories.

Key Terms

Systolic PressureThe top number — pressure when the heart beats and pumps blood. Target: below 120 mmHg.
Diastolic PressureThe bottom number — pressure when the heart rests between beats. Target: below 80 mmHg.
HypertensionConsistently elevated BP (≥130/80), a major risk factor for heart disease, stroke, and kidney failure.
MAPMean Arterial Pressure — average pressure during one cardiac cycle. Indicates organ perfusion adequacy.
ISHIsolated Systolic Hypertension — systolic ≥130 with diastolic <80. Most common type in older adults.
White Coat SyndromeElevated readings in clinical settings due to anxiety, while home readings are normal. Affects ~20% of people.

Real-World Examples

Example 1

Normal Reading

Input: Systolic 118, Diastolic 76, Age 40

Result: Normal BP. MAP = 90 mmHg, PP = 42 mmHg. Gauge pointer in the green zone. Maintain healthy habits.

Example 2

Isolated Systolic HTN

Input: Systolic 148, Diastolic 74, Age 62

Result: Stage 2 HTN with ISH detected. Wide pulse pressure (74 mmHg). Lifestyle + medication evaluation recommended.

Example 3

Elevated with Risk Factors

Input: Systolic 126, Diastolic 78, Age 55, Smoker, Cholesterol 250

Result: Elevated BP. Risk Analysis shows intermediate 10-year CVD risk. Quitting smoking could reduce risk by ~5%.

Managing Your Blood Pressure

The Silent Killer

High blood pressure often has no symptoms until serious damage occurs. It is the leading modifiable risk factor for heart disease, stroke, and kidney failure. Regular monitoring is the only way to detect it early.

Why Tracking Matters

A single reading tells a limited story. Blood pressure fluctuates throughout the day. Logging multiple readings over time helps identify true trends — whether you're improving with lifestyle changes or need medical intervention. The AHA recommends measuring twice daily for 5-7 days to establish a baseline.

Lifestyle Changes That Work

The DASH diet can lower systolic pressure by 8-14 mmHg. Regular exercise reduces it 4-9 mmHg. Reducing sodium to under 1,500 mg/day saves another 2-8 mmHg. Combined, these changes can be as effective as a first-line medication.

Understanding Your Risk

Blood pressure is just one factor in cardiovascular risk. Age, cholesterol, smoking, and diabetes all contribute. A 10-year risk assessment gives a more complete picture than BP alone and helps guide treatment decisions — including whether medication is warranted for borderline readings.

Frequently Asked Questions

Why are my blood pressure readings different each time?

Blood pressure naturally fluctuates based on activity, stress, hydration, posture, and time since your last meal. The AHA recommends taking 2-3 readings one minute apart at the same time each day and averaging them.

What is the difference between systolic and diastolic pressure?

Systolic (top number) measures pressure when your heart beats. Diastolic (bottom number) measures pressure when your heart rests. Elevated systolic is a stronger predictor of cardiovascular events in adults over 50, while elevated diastolic is more concerning in younger adults.

What is isolated systolic hypertension?

ISH occurs when systolic is 130+ mmHg while diastolic remains below 80. It is the most common form of hypertension in older adults, caused by arterial stiffening. ISH significantly increases stroke and heart attack risk.

How does salt raise blood pressure?

Excess sodium causes water retention, increasing blood volume and pressure. About 50-60% of hypertensive people are salt-sensitive. The AHA recommends no more than 2,300 mg/day, ideally under 1,500 mg.

Can exercise temporarily spike blood pressure?

During intense exercise, systolic can temporarily rise above 200 mmHg, which is normal. However, an exaggerated response (above 210 in men or 190 in women) may predict future hypertension. If you have uncontrolled hypertension (above 180/110), consult your doctor before vigorous exercise.

How accurate is the 10-year risk estimate?

Our simplified estimate is for educational purposes. It uses a Framingham-style approach but is not a substitute for the full ACC/AHA Pooled Cohort Equations. For clinical risk scoring, consult your physician who can factor in additional variables.