Blood Pressure Calculator

Free blood pressure calculator with AHA classification, Mean Arterial Pressure (MAP), pulse pressure analysis, and hypertensive crisis detection. Home and clinic thresholds.

Top number — pressure when heart beats

Bottom number — pressure when heart rests

Home readings use slightly lower thresholds (NICE/ESH guidelines).

Your Blood Pressure

118/76mmHg
Normal
118
Low
Normal
Elevated
Stage 1
Stage 2
Crisis

Scale position based on systolic reading. Your category considers both systolic and diastolic values.

This reading is within the healthy range. Maintain a healthy lifestyle with regular exercise, balanced diet, and stress management.

Key Numbers

Your reading breakdown at a glance

MAP

90.0mmHg

Pulse Pressure

42mmHg

Systolic

118mmHg

Diastolic

76mmHg

Derived Metrics

MAP and pulse pressure calculated from your reading

Mean Arterial Pressure90.0mmHg
Low (<60)Normal (70–100)High (>110)
Pulse Pressure42mmHg
Narrow (<25)Normal (25–40)Wide (>60)

Clinical Insights

Follow-up schedule and risk indicators

Recommended Follow-Up

Recheck in 1–2 years

Urgency Level

No Action Needed

Blood Pressure Categories

NICE/ESH Classification (home readings)

Low
< 90/< 60
Normal
< 135/< 85
Stage 1 HTN
135–149/85–94
Stage 2 HTN
≥ 150/≥ 95
Crisis
> 180/> 120

Source: NICE/ESH Guidelines (home thresholds). Values in mmHg. Category determined by the higher of systolic or diastolic.

What Is Blood Pressure?

Blood pressure is the force of blood pushing against artery walls as your heart pumps. It is measured in mmHg and recorded as two numbers.

Systolic (Top)

Pressure when heart beats and pushes blood out

Diastolic (Bottom)

Pressure when heart rests between beats

Example: A reading of 120/80 mmHg means systolic = 120, diastolic = 80. Both numbers matter — the higher classification determines your category.

Mean Arterial Pressure (MAP) Formula

MAP estimates average arterial pressure during one cardiac cycle. It matters more clinically because the heart spends ~⅔ of each cycle in diastole.

Formula

MAP = (SBP + 2 × DBP) ÷ 3

Low

< 60

Poor perfusion

Normal

70–100

Adequate flow

High

> 110

Vascular strain

Example: BP 130/85 → MAP = (130 + 2×85) ÷ 3 = 300 ÷ 3 = 100 mmHg

Understanding Pulse Pressure

Pulse pressure reflects the force of each heartbeat and arterial stiffness. It is an independent cardiovascular risk marker.

Formula

Pulse Pressure = Systolic − Diastolic

< 25Narrow

Low cardiac output, heart failure, blood loss

25–40Normal

Healthy arterial compliance and cardiac output

41–60Mildly Elevated

Common with age as arteries stiffen

> 60Widened

Arterial stiffness — independent CVD risk factor

How to Measure Blood Pressure Accurately

Accurate readings require proper technique. Follow these steps:

1

Sit quietly for 5 minutes. No caffeine, smoking, or exercise within 30 min.

2

Back supported, feet flat, arm at heart level on a table.

3

Use a properly sized cuff — bladder should encircle 80% of upper arm.

4

Take 2–3 readings 1 minute apart. Record the average.

Home vs Clinic: Home readings are typically 5–10 mmHg lower due to the “white coat effect.” NICE NG136 uses different thresholds for home/ABPM readings — Stage 1 at 135/85, Stage 2 at 150/95, compared to clinic thresholds of 130/80 and 140/90.

Blood Pressure Classification Chart

Complete AHA/ACC 2017 blood pressure categories with recommended actions.

CategorySystolicDiastolicAction
Hypotension
< 90< 60See doctor if symptomatic
Normal
< 120< 80Recheck in 1–2 years
Elevated
120–129< 80Lifestyle changes
Stage 1 HTN
130–13980–89Lifestyle changes; medication based on risk
Stage 2 HTN
≥ 140≥ 90Medication + lifestyle
Crisis
> 180> 120Emergency care

Source: 2017 ACC/AHA High Blood Pressure Clinical Practice Guidelines. Values in mmHg.

Frequently Asked Questions

Common questions about blood pressure readings, MAP, pulse pressure, and hypertension categories

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