Why the average
Single readings jump around: a stressful morning, a coffee too close to the reading, a cuff that slipped. The average of many readings smooths that out. The AMA's home monitoring guide asks doctors to average all the readings from the monitoring period and use that average for decisions.
How to do it by hand
- Collect all your readings for the period, for example 7 days of morning and evening readings, two each time. That is up to 28 readings.
- Add up the top numbers (systolic) on their own.
- Add up the bottom numbers (diastolic) on their own.
- Divide each total by the number of readings.
- Round to the nearest whole number. That is your average, for example 127/81.
Never average "128/82" as a single number. The top and bottom numbers are always averaged separately.
A worked example
Six readings from three mornings:
| Reading | Systolic | Diastolic |
|---|---|---|
| Mon, 1st | 132 | 84 |
| Mon, 2nd | 128 | 82 |
| Tue, 1st | 126 | 80 |
| Tue, 2nd | 124 | 79 |
| Wed, 1st | 130 | 83 |
| Wed, 2nd | 127 | 81 |
| Total | 767 | 489 |
| Average (÷ 6) | 127.8 → 128 | 81.5 → 82 |
The average for these three mornings is 128/82.
How many readings do you need?
The AMA suggests 7 days, morning and evening, with two readings each time, and at least 12 readings over 3 days before a decision is made. More readings make the average more reliable.
Morning and evening separately
Your doctor may want the morning and evening averages as well as the overall one, because many people run higher in the morning. Our log keeps morning and evening in separate columns, so you can add each column on its own.
What the average means
Compare your average with the target your doctor gave you. The 2025 guideline from the American Heart Association, the American College of Cardiology and other groups keeps the same categories for adults; see the blood pressure chart. Home averages and office readings are not always the same, and your doctor will interpret yours alongside everything else they know about you.
Not medical advice. This guide is general information. Your target, how often to measure and your treatment come from your doctor, who knows your situation.
Use the average calculatorPaste or type your readings and get the average in one step.Questions
Do I average the first and second reading, or keep both?
Write both on your log and include both in the average. That is how the AMA's home monitoring guide describes it.
Should I leave out a reading that looks wrong?
Not on your own. If you think a reading was a mistake (cuff slipped, you were talking), note it on the log and ask your doctor. Leaving out high readings makes the average look better than it is.
Do I average my pulse too?
You can, in the same way. It is not part of the blood pressure average, but some doctors like to see it.
Is a home average of 135/85 the same as 135/85 at the office?
Not exactly. Home and office readings can differ, and guidelines treat them a little differently. Your doctor will tell you what your home average means for you.
Can I just use my monitor's average?
If your monitor averages readings for you, that is fine, as long as it covers the right days and includes all readings. Check the manual.
Sources
- American Medical Association. 7-step SMBP quick guide (self-measured blood pressure)
- American Heart Association. Monitoring Your Blood Pressure at Home
- 2025 AHA/ACC/AANP/AAPA/ABC/ACCP/ACPM/AGS/AMA/ASPC/NMA/PCNA/SGIM Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults. Hypertension 2025;82(10):e212–e316