Blood Pressure Calculator
Enter your top (systolic) and bottom (diastolic) numbers to see which blood pressure category they fall into, based on the ACC/AHA 2017 guidelines.
A single reading can mislead. What your doctor uses is an average over days or weeks.
How the categories work
Under the ACC/AHA 2017 guideline, the higher of your two numbers decides the category:
Normal: under 120 and under 80
Elevated: 120-129 and under 80
Stage 1: 130-139 or 80-89
Stage 2: 140+ or 90+
Crisis: over 180 or over 120
Source: 2017 ACC/AHA High Blood Pressure Guideline.
Frequently asked questions
Which number matters more, top or bottom?
Both matter, and the higher category of the two decides your classification. In older adults the systolic (top) number is often the stronger predictor of risk.
What is the white-coat effect?
Some people read higher at the doctor's office than at home due to stress. That is why home readings, averaged over time, are so useful.
How should I measure blood pressure?
Sit and rest 5 minutes, feet flat, arm supported at heart level, no caffeine or exercise beforehand. Take two readings a minute apart and average them.
How often should I check?
If you are monitoring, most guidance suggests morning and evening readings for a week, logged so your clinician can see the trend.
Medical disclaimer: This calculator is for general information and education only. It is an estimate, not medical advice, diagnosis or treatment. Always talk to your doctor or midwife about your health and any decisions.