READING LOOKUP

Blood pressure 100 over 50 to 85

A top number of 100 is in the Normal range. The bottom number decides the rest: under 80 stays Normal, 80 to 89 is Stage 1, and 90 or higher is Stage 2.

Reviewed by Kaustubh Dabhadkar, MD, MPH, FACC, board-certified cardiologist. Categories follow the 2025 ACC/AHA guideline for adults.

100 over what? The quick answer

100/50 to 79: Normal
100/80 to 85: Stage 1 hypertension

Every 100 reading

Pulse pressure is the top number minus the bottom number. MAP (mean arterial pressure) is the bottom number plus a third of the pulse pressure.

Reading	Category	Pulse pressure	MAP
100/50	Normal	50	66.7
100/51	Normal	49	67.3
100/52	Normal	48	68
100/53	Normal	47	68.7
100/54	Normal	46	69.3
100/55	Normal	45	70
100/56	Normal	44	70.7
100/57	Normal	43	71.3
100/58	Normal	42	72
100/59	Normal	41	72.7
100/60	Normal	40	73.3
100/61	Normal	39	74
100/62	Normal	38	74.7
100/63	Normal	37	75.3
100/64	Normal	36	76
100/65	Normal	35	76.7
100/66	Normal	34	77.3
100/67	Normal	33	78
100/68	Normal	32	78.7
100/69	Normal	31	79.3
100/70	Normal	30	80
100/71	Normal	29	80.7
100/72	Normal	28	81.3
100/73	Normal	27	82
100/74	Normal	26	82.7
100/75	Normal	25	83.3
100/76	Normal	24	84
100/77	Normal	23	84.7
100/78	Normal	22	85.3
100/79	Normal	21	86
100/80	Stage 1	20	86.7
100/81	Stage 1	19	87.3
100/82	Stage 1	18	88
100/83	Stage 1	17	88.7
100/84	Stage 1	16	89.3
100/85	Stage 1	15	90

What to do with a 100 reading

Keep checking now and then, the same way each time. Your category comes from the average of many home readings, so one number tells you less than a week of them.

With a bottom number of 80 or higher, the reading is at or above 130/80. In that case: sit quietly for 5 minutes and take two readings a minute apart. If home readings average in this range over a week, share them with your doctor, who will look at them alongside your overall heart risk.

Readings move from minute to minute, and the first one usually runs a few points higher. The home measuring guide covers how to get a reading you can trust, and the 7-day home average turns a week of readings into the number your doctor uses. To check any reading, use the category checker.

Common questions

Is 100/70 high blood pressure?

100/70 is in the Normal range of the 2025 ACC/AHA chart, with a top number under 120 and a bottom number under 80. One reading is a snapshot: the guideline places you by the average of readings taken on separate occasions.

Is 100/80 high blood pressure?

100/80 is in the Stage 1 hypertension range of the 2025 ACC/AHA chart, because the bottom number is 80 to 89. One reading is a snapshot: the guideline places you by the average of readings taken on separate occasions.

What is the MAP of 100/80?

About 86.7 mmHg. Mean arterial pressure is the bottom number plus a third of the pulse pressure: 80 + 20/3. The pulse pressure is 20.

This page is educational and does not provide medical advice, diagnosis, or treatment. Categories describe numbers for adults; they are not a diagnosis, and they are not a substitute for care from your own doctor.

SOURCES

Jones DW, et al. 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 (Circulation, 2025): Blood pressure categories (normal under 120/80, elevated 120 to 129 and under 80, stage 1 130 to 139 or 80 to 89, stage 2 140 or 90 and higher); the higher category counts when the two numbers disagree; severe hypertension above 180/120; PREVENT for risk estimation
Understanding Blood Pressure Readings (American Heart Association, reviewed August 14, 2025): Category chart for adults; severe hypertension and hypertensive emergency rows; call 911 above 180/120 with symptoms

Track this automatically with BP Log.

The free iPhone app times two readings a minute apart, averages them, keeps your morning and evening numbers apart, and builds a report for your doctor.

Other ways to track: printable log now, desktop and Excel coming soon