Normal blood pressure for adults is less than 120/80 mm Hg. That first number (systolic) measures the force when your heart beats, and the second number (diastolic) measures the force when your heart rests between beats. Both numbers need to fall below those thresholds for your reading to count as normal under current guidelines from the American Heart Association and American College of Cardiology.
Blood Pressure Categories for Adults
The 2025 AHA/ACC guidelines break blood pressure into four categories, and these apply equally to all adults regardless of age. Older guidelines used to set a higher threshold for people over 65, but that distinction was dropped in 2017.
- Normal: below 120 systolic and below 80 diastolic
- Elevated: 120 to 129 systolic and below 80 diastolic
- Stage 1 hypertension: 130 to 139 systolic or 80 to 89 diastolic
- Stage 2 hypertension: 140 or higher systolic or 90 or higher diastolic
If your systolic and diastolic numbers fall into two different categories, the higher category is the one that applies. So a reading of 135/75 counts as Stage 1 hypertension even though the diastolic number looks fine.
Anything above 180/120 is considered a hypertensive emergency and requires immediate medical attention.
What Pulse Pressure Tells You
Pulse pressure is the gap between your systolic and diastolic numbers. If your blood pressure is 120/80, your pulse pressure is 40, which is considered healthy. A pulse pressure consistently above 60 is a risk factor for heart disease, particularly in older adults, because it signals that the walls of your largest arteries have stiffened and lost their flexibility.
Normal Blood Pressure in Children
There is no single “normal” number for children. Pediatric blood pressure is evaluated using percentile charts that account for age, sex, and height. A child’s reading is compared to other children of the same size and age, and readings at or above the 95th percentile are considered high. This means a number that’s perfectly normal for a tall 12-year-old could be concerning for a smaller 8-year-old.
Why Your Reading Might Be Wrong
Small details during measurement can shift your numbers by enough to push a normal reading into the elevated range, or vice versa. A systematic review of clinical measurement errors found these common culprits:
- Not resting first: Skipping a 10-minute rest period can inflate your systolic reading by 4 to 12 points.
- Unsupported arm: Letting your arm dangle instead of resting it on a surface adds roughly 5 points to systolic.
- Arm below heart level: Holding your arm too low can raise the reading by anywhere from 4 to 23 systolic points.
- Wrong cuff size: A cuff that’s too small inflates your reading by 2 to 11 points. A cuff that’s too large can lower it by up to 4 points.
For the most accurate reading, sit quietly for at least five minutes, rest your arm on a flat surface at heart height, keep your feet flat on the floor, and make sure the cuff fits snugly around your upper arm without overlapping. If your numbers seem surprising, measure again on a different day before drawing conclusions.
Normal Pressure Inside the Eye
If you searched “normal pressure” in the context of eye health, the standard range for intraocular pressure is roughly 9 to 21 mm Hg, with an average around 14 to 15 mm Hg. Readings above 21 have traditionally been the threshold for concern about glaucoma, though some people develop glaucoma at lower pressures and others tolerate higher pressures without damage. A large population study found that after adjusting for body and eye characteristics, the tighter normal range was 9 to 18 mm Hg. Your eye doctor checks this during routine exams using a quick, painless puff of air or a gentle contact measurement.
Normal Pressure Inside the Skull
The brain and spinal cord float in cerebrospinal fluid that exerts its own pressure. In a healthy adult, intracranial pressure ranges from 7 to 15 mm Hg. This isn’t something you’d measure at home; it’s relevant in hospital settings after head injuries, brain surgery, or when a condition called normal pressure hydrocephalus is suspected.
Normal pressure hydrocephalus is a condition where excess fluid builds up in the brain’s cavities, but the measured pressure often falls within or near the normal range, which is how it got its name. The term is somewhat misleading, because the pressure isn’t always truly normal. The hallmark symptoms are a shuffling, unsteady walk, urinary incontinence, and cognitive decline resembling dementia. Diagnosis typically requires gait problems plus at least one of the other two symptoms. It’s treatable with a surgically placed shunt that drains excess fluid, and the walking difficulties in particular often improve afterward.
Normal Atmospheric Pressure
Standard atmospheric pressure at sea level is 14.7 pounds per square inch (psi), or 1013.25 hectopascals (also written as millibars). This is the baseline that weather forecasters use. Pressure drops as you gain altitude, which is why your ears pop on an airplane and why weather systems with low pressure tend to bring storms. The International Space Station maintains its cabin at the same 14.7 psi density as Earth’s surface so astronauts can breathe normally.