Blood Pressure Calculator: AHA Category and Pulse Pressure

Reading your blood pressure with the AHA/ACC categories

The tool places a systolic/diastolic reading in the American Heart Association categories: normal below 120/80 mmHg, elevated at 120-129 with a diastolic below 80, stage 1 hypertension from 130 or 80, stage 2 from 140 or 90. It also computes pulse pressure (systolic minus diastolic) and mean arterial pressure (MAP).

Classification rule

The worse of the two numbers decides. The tool checks in this order: systolic above 180 or diastolic above 120 (most severe category); ≥ 140 or ≥ 90 (stage 2); 130-139 or 80-89 (stage 1); 120-129 with a diastolic below 80 (elevated); otherwise normal.

Formulas

• Pulse pressure: PP = SBP − DBP
• Mean arterial pressure: MAP = DBP + PP / 3

Example

With the default reading of 124/82 mmHg, the systolic value alone would be "elevated", but the diastolic of 82 puts the reading in stage 1. PP = 124 − 82 = 42 mmHg; MAP = 82 + 42 / 3 = 96.0 mmHg. At 128/76 mmHg the category is "elevated", PP = 52 mmHg and MAP = 93.3 mmHg.

Assumptions and limits

A single reading is not a diagnosis: guidelines rely on the average of several resting readings taken on different days. Above 180/120 the AHA separates severe hypertension (no symptoms) from a hypertensive emergency (with symptoms); the tool does not ask about symptoms. It does not flag low blood pressure either: 85/55 mmHg comes out as "normal". The 40-60 mmHg pulse pressure range it shows is an indicative value, not verified. European guidelines (ESC 2024) use different cut-offs (elevated BP at 120-139/70-89 mmHg, hypertension from 140/90 mmHg), which the tool does not apply. The result is an estimate and does not replace a doctor's opinion.

Sources and dates: categories from the 2017 AHA/ACC guideline, unchanged on the AHA page last reviewed on 14 August 2025 (American Heart Association, Understanding Blood Pressure Readings); 2025 AHA/ACC high blood pressure guideline, target below 130/80 mmHg (American College of Cardiology, overview of the 2025 guideline); 2024 ESC guidelines on elevated blood pressure and hypertension, cited without a link (checked on 14/10/2026)

Frequently Asked Questions

What blood pressure is considered normal?

According to the American Heart Association, blood pressure is normal when systolic is below 120 mmHg and diastolic below 80 mmHg. A systolic of 120-129 with a diastolic below 80 is called elevated. These cut-offs date from 2017 and were kept in 2025.

At what reading does high blood pressure start?

Under AHA/ACC rules, hypertension starts at 130 mmHg systolic or 80 mmHg diastolic (stage 1) and becomes stage 2 from 140 or 90. The 2024 ESC European guidelines set the hypertension threshold at 140/90 mmHg. A diagnosis relies on several readings, not one.

How are pulse pressure and mean arterial pressure calculated?

Pulse pressure is systolic minus diastolic: 124/82 gives 42 mmHg. Mean arterial pressure is estimated as diastolic + pulse pressure / 3, which is 82 + 14 = 96 mmHg in this example.

What should I do if my reading is above 180/120 mmHg?

The AHA advises waiting one minute and measuring again. If it stays that high without symptoms, contact a healthcare professional promptly; with chest pain, shortness of breath, vision changes or weakness, call emergency services (911 in the US, 112 in Europe).

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.