Blood Pressure Calculator
Two Numbers, Three Calculations
A blood pressure reading is really two measurements at once — systolic (pressure during a heartbeat) over diastolic (pressure between beats) — and those two numbers can be combined in different ways depending on what you're trying to understand. This tool covers the three most common: the standard AHA category, mean arterial pressure, and pulse pressure.
Blood Pressure Categories
| Category | Systolic | Diastolic | |
|---|---|---|---|
| Normal | Below 120 | and | Below 80 |
| Elevated | 120 – 129 | and | Below 80 |
| Hypertension Stage 1 | 130 – 139 | or | 80 – 89 |
| Hypertension Stage 2 | 140 or higher | or | 90 or higher |
| Hypertensive Crisis | Above 180 | and/or | Above 120 |
Values are in mmHg. A hypertensive crisis reading calls for immediate medical attention regardless of the other number.
The Other Two Formulas
Pulse Pressure = Systolic − Diastolic
Typical MAP values fall in the 70–100 mmHg range; typical pulse pressure falls in the 40–60 mmHg range. MAP reflects average perfusion pressure across the whole cardiac cycle, while pulse pressure reflects the force generated by each individual heartbeat.
Why Each Calculation Gets Used
- Category classification — the most common use, comparing a home or clinic reading against standard reference ranges.
- Mean arterial pressure — used in critical care settings to assess organ perfusion, since it better reflects average pressure than either number alone.
- Pulse pressure — a widening pulse pressure over time is sometimes tracked as an indicator of arterial stiffness.
How to Use This Calculator
- Select which calculation you want: BP Category, Mean Arterial Pressure, or Pulse Pressure.
- Enter your systolic reading in mmHg.
- Enter your diastolic reading in mmHg.
- Select Calculate to see the result.
Related Calculations
Check your cardiovascular risk picture further with the Cholesterol Ratio Calculator.