Blood Pressure Chart
Compare one adult blood pressure reading with American Heart Association categories. Enter the top and bottom numbers to see which one determines the category, with a separate low-number flag when relevant.
A reading category is not a diagnosis. This chart is for adults aged 18 or older who are not pregnant. It does not set personal treatment targets or assess symptoms.
Use the calculatorCheck the Two Numbers on Your Monitor
Use a recorded reading in mmHg. This tool compares numbers; it does not measure blood pressure.
Your reading breakdown will appear here
Enter both numbers and confirm the chart’s adult scope. A category describes this entry, not your overall health.
An OR rule for high readings
For example, 128/84 is in the stage 1 range because the bottom number is 84.
Low numbers stay visible
A low diastolic flag does not cancel an elevated systolic category.
No automatic treatment advice
The page does not prescribe medication, change doses or label any reading “safe”.
Your reading, separated into two parts
This is a single-reading comparison. It is not a diagnosis, a personal target or a clearance to ignore symptoms.
Medical disclaimer: This educational chart does not diagnose hypertension, identify organ damage or replace professional assessment. It is not an emergency triage service. Do not start, stop or change medicines based on this page. Follow the plan given by your care team and seek urgent help for concerning symptoms.
Why the category was selected
The AHA chart uses “and” for normal/elevated and “or” for higher stages. A separate low-number flag is not another AHA hypertension stage. No readings are averaged or stored.
The adult chart behind the result
Read each row’s AND / OR condition; do not match only the top number.
| AHA chart category | Systolic (mmHg) | Diastolic (mmHg) |
|---|---|---|
| Normal range | Below 120 | AND below 80 |
| Elevated range | 120–129 | AND below 80 |
| Stage 1 range | 130–139 | OR 80–89 |
| Stage 2 range | 140 or higher | OR 90 or higher |
| Severe high range | Higher than 180 | OR higher than 120 |
Verify category thresholds in the AHA adult chart. The severe category uses strict “higher than” cut-offs. At exactly 180 systolic or 120 diastolic, this implementation also displays a precautionary notice without changing the AHA category.
The lower number can decide
128 systolic is elevated, but 84 diastolic is in the stage 1 range. The combined reading uses stage 1; the two categories are not averaged.
A lower diastolic is not an override
150 systolic is in the stage 2 range even with diastolic below 80. A normal-range component does not cancel the higher one.
One very high component is enough
190 systolic exceeds the AHA severe-high cut-off. Diastolic does not also need to exceed 120. Read the symptom-dependent urgent guidance.
Interpret the reading without losing the context
Measurement conditions, mixed components and symptoms cannot be reduced to a green badge.
One reading and a diagnosis are different
A monitor gives a reading at a particular time. Diagnosing hypertension requires professional interpretation of repeated measurements and the relevant clinical context. This page cannot establish a diagnosis from one pair of numbers.
High systolic and low diastolic can coexist
For 150/50, the systolic component keeps the combined reading in the stage 2 range. The diastolic number also receives a low-number flag. Showing both avoids the false reassurance of replacing the high category with “low blood pressure”.
The exact cut-off is visible
180/120 remains in the AHA stage 2 numeric range because the severe row says higher than 180 or higher than 120. This page adds a precaution at equality: the boundary is not a reason to ignore a very high reading or symptoms.
A low-number flag needs context
A systolic entry below 90 or a diastolic entry below 60 triggers a separate flag, following the NIH/NIA description. Low readings may be usual for some people, but new symptoms such as dizziness or fainting need assessment. A number alone does not establish a cause.
Home and clinic criteria are not interchangeable
This checker names the AHA reading framework. Other guidelines use different diagnostic thresholds and multi-reading protocols. NICE, for example, distinguishes clinic readings from home or ambulatory averages; do not apply a diagnosis threshold to one home entry.
Keep the record, not just the label
Record both values, the time and relevant circumstances for your care team. This calculator stores no log and does not compare trends, assess an irregular pulse or derive a cardiovascular risk percentage.
Before a routine home measurement
Use a validated upper-arm monitor with a cuff that fits. Avoid smoking, caffeine and exercise for 30 minutes beforehand; empty your bladder. Rest quietly for at least five minutes, support your back, keep feet flat and place the cuff on a bare upper arm supported at heart level. Stay still and do not talk.
For routine recording, the AHA advises two readings one minute apart. Keep both for your care team; this checker handles each separately. These preparation steps must not delay emergency help when concerning symptoms are present.
AHA home-monitoring instructions explain the measurement setup. NIH/NIA guidance provides low-reading context, and NICE NG136 explains clinic and home-average diagnostic pathways.
Helpful resources
Related health tools and official references for checking this page’s thresholds and measurement advice.
Useful resources
References support the stated framework; they do not endorse this website. Bhavin Sheth is credited for page maintenance, not as a medical reviewer. This tool has not been independently clinically validated.
Questions about reading categories and cut-offs
Clarify what the chart compares before relying on a label.
Does one result diagnose high blood pressure?
No. This is a comparison of one reading with named AHA ranges. Diagnosis and personal targets require professional assessment, usually including repeated measurements.
Which number decides when the two ranges differ?
The higher component category decides. For example, 128/84 is in the stage 1 range because the diastolic component is 84.
Why is 150/50 not simply labelled low?
The systolic component is in the stage 2 range. A separate low-diastolic flag is shown without hiding the high systolic category.
Is exactly 180/120 in the severe AHA row?
The AHA severe row says higher than 180 systolic or higher than 120 diastolic. Exactly 180/120 remains in its stage 2 numeric range. This tool also adds a precautionary notice at equality; the boundary is not reassurance.
Can this tool tell whether I am having an emergency?
No. It does not assess symptoms or organ damage. Concerning new symptoms require urgent assessment regardless of the numeric category. Use your local emergency service when emergency symptoms are present.
Can I use this during pregnancy or for a child?
No. The implementation is scoped to nonpregnant adults aged 18 or older. Pregnancy and children need their own clinical guidance and cannot be assessed by this general chart.
Does the checker average readings or set a medicine dose?
No. It compares one pair of numbers and does not average, store trends or recommend medication changes. Keep your own reading record and follow your care team’s plan.
Are the entries uploaded or saved?
This calculator script keeps entries in browser memory without uploading them or saving them to browser storage. Fonts and other website scripts may make their own requests; this statement applies only to this calculator script.