Blood Pressure Category Calculator
Where a reading falls on the ACC/AHA scale.
Classify a blood pressure reading using the 2017 ACC/AHA categories, from normal through hypertensive crisis, with pulse pressure and MAP.
A single reading is not a diagnosis. Measure seated and rested, take two or three readings a minute apart, and average them.
Blood pressure
118/76
Normal
How the Blood Pressure Category Calculator works
The 2017 ACC/AHA guideline lowered the threshold for hypertension from 140/90 to 130/80, which reclassified a large share of the adult population overnight. Categories are assigned by whichever of the two numbers is worse.
Also known as: is my blood pressure normal · hypertension stage calculator · BP category chart
Two sets of categories that disagree
The American College of Cardiology and American Heart Association revised their thresholds in 2017, defining hypertension as 130 over 80 or above. Normal is under 120 over 80, elevated is 120 to 129 systolic with diastolic under 80, stage 1 hypertension is 130 to 139 or 80 to 89, and stage 2 is 140 over 90 or above.
The UK National Institute for Health and Care Excellence and the European Society of Cardiology retain a threshold of 140 over 90 for the diagnosis of hypertension in clinic, with 135 over 85 for home and ambulatory measurement.
That disagreement is genuine and it means the same reading is classified differently depending on which guidance applies. Someone at 134 over 84 has stage 1 hypertension under American guidance and high-normal blood pressure under European guidance, which is why quoting a category without saying which guideline it came from is unhelpful.
Measuring it properly
Technique changes readings substantially. Sitting quietly for five minutes beforehand, back supported, feet flat, arm supported at heart level, no talking during the measurement, and no caffeine or exercise in the preceding half hour.
Cuff size matters more than almost anything else. A cuff too small for the arm overestimates, sometimes by a large margin, and undersized cuffs are a common and consequential error.
A single reading diagnoses nothing. Guidelines specify multiple readings across separate occasions, and increasingly favour home or ambulatory monitoring over clinic readings for exactly that reason.
White coat and masked hypertension
White coat hypertension is blood pressure that is high in clinic and normal at home, affecting a meaningful proportion of people with raised clinic readings. It carries lower risk than sustained hypertension and is not entirely benign.
Masked hypertension is the reverse: normal in clinic and high at home. It is easier to miss and it carries risk comparable to sustained hypertension.
Both are reasons why ambulatory or home monitoring is now recommended before diagnosis in most guidelines. A diagnosis made on clinic readings alone will label some people who do not have hypertension and miss some who do.
What the numbers mean for risk
The relationship between blood pressure and cardiovascular risk is continuous and starts well below the diagnostic thresholds. There is no level below which risk stops falling within the range observed.
Which means the categories are decision points for treatment rather than descriptions of safety. The thresholds mark where the benefits of intervention are judged to exceed the costs, and that judgement differs between guideline committees, which is why the thresholds differ.
Treatment decisions in practice use overall cardiovascular risk rather than blood pressure alone, incorporating age, sex, smoking, cholesterol, diabetes and family history. A reading of 145 over 90 leads to different advice in a 40 year old non-smoker than in a 65 year old with diabetes.
When a reading is urgent
A reading at or above 180 over 120 warrants prompt medical attention, and immediate attention if accompanied by symptoms: chest pain, breathlessness, severe headache, visual changes, weakness, difficulty speaking or back pain.
Those symptoms with a very high reading may indicate a hypertensive emergency with organ damage occurring, which is treated urgently in hospital.
Very low readings with symptoms of poor perfusion, dizziness, confusion or fainting, also warrant attention. This page classifies a pair of numbers against published tables and cannot assess anyone, and any reading that is concerning belongs with a clinician the same day rather than with a website.
Where to go next
The Blood Pressure Category question rarely arrives on its own. These are the ones that usually come with it:
- Mean Arterial Pressure Calculator — MAP from systolic and diastolic, with perfusion thresholds.
- Cholesterol Ratio Calculator — Total:HDL, LDL:HDL and triglyceride ratios.
- BMI Calculator — Body mass index with category and healthy weight range.
- Calorie & BMR Calculator — Daily calorie needs for losing, holding, or gaining weight.
Not medical advice. This calculator gives a general estimate, not medical advice. It cannot account for your individual health, medical history, or medication. Talk to a qualified healthcare professional before acting on any result.
Frequently asked questions
What are the blood pressure categories?
Normal: under 120 and under 80. Elevated: 120-129 and under 80. Stage 1 hypertension: 130-139 or 80-89. Stage 2: 140+ or 90+. Hypertensive crisis: above 180 or above 120, which needs immediate medical attention.
Which number matters more, systolic or diastolic?
Systolic is the stronger predictor of cardiovascular risk after about age 50, as arteries stiffen. Below 50, diastolic carries more weight. Categories use whichever number falls in the higher band, so either alone can determine the stage.
How should blood pressure be measured properly?
Seated, back supported, feet flat, arm at heart level, after five minutes of rest, with no caffeine or exercise in the preceding 30 minutes. Take two or three readings a minute apart and average them. A single casual reading is not a diagnosis.
What is white coat hypertension?
Readings that are elevated in a clinical setting but normal at home, affecting perhaps 15-30% of people diagnosed in clinic. It is the main reason home or 24-hour ambulatory monitoring is recommended before starting treatment.
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