🩺Blood Pressure Checker

About this tool

Enter a reading as systolic over diastolic, the top and bottom numbers, with your pulse if you like. Add more rows to average several readings. The checker shows the average, its category with a short explanation, the pulse pressure, the mean arterial pressure and a table of every category with yours highlighted.

How blood pressure readings are classified

Systolic pressure is the force in your arteries when the heart beats, and diastolic is the pressure between beats, both in millimetres of mercury (mmHg). This checker uses the American College of Cardiology and American Heart Association categories. Normal is below 120 and below 80. Elevated is 120–129 with a diastolic below 80. Stage 1 high blood pressure is 130–139 or 80–89, and stage 2 is 140 or more, or 90 or more. Above 180 and/or above 120 is a hypertensive crisis. The higher category of the two numbers applies, so 128/78 is elevated while 128/82 is stage 1. Because blood pressure changes from minute to minute, one reading means little. Three readings of 142/91, 136/88 and 134/86 average 137/88, which is stage 1. Measure at the same time of day, seated and rested for five minutes, with your arm supported at heart level, and average two or three readings taken a minute apart. Other guidelines draw the lines differently. The UK's NICE treats 140/90 in a clinic, or 135/85 at home, as high. Honest limits: only a health professional can diagnose high blood pressure or change treatment, and you should seek help straight away if a very high reading comes with chest pain, breathlessness, weakness or problems with vision or speech. Not medical advice. The heart rate zones calculator, the BMI calculator and the waist-to-height calculator cover related measures. Heart rate zones explained: how they're calculated and what each one trains explains heart rate.

Frequently asked questions