Why use this calculator
Blood pressure is one of the most important indicators of cardiovascular health, yet most people don't know what their reading means. This calculator translates your numbers into a clear category and action guidance — so you know whether to maintain, improve, or seek medical care.
How to use it
Enter your systolic (top) and diastolic (bottom) numbers from a blood pressure reading. Take your reading after resting for 5 minutes, sitting quietly. If you have multiple readings, use the average of 2-3 readings for more accuracy.
The formula
Categories based on AHA/ACC 2017 guidelines: Normal <120/<80. Elevated 120-129/<80. Stage 1 Hypertension 130-139/80-89. Stage 2 Hypertension ≥140/≥90. Crisis ≥180/≥120. MAP = Diastolic + (Systolic − Diastolic) ÷ 3.
Worked examples
Reading of 115/75
Normal — healthy blood pressure, maintain current lifestyle
Reading of 145/95
Hypertension Stage 2 — medical attention required, likely needs medication
When people use it
- Checking your blood pressure reading at home
- Understanding a reading from a GP visit
- Monitoring blood pressure after lifestyle changes
- Assessing cardiovascular risk
Tips
- For the most accurate reading: sit quietly for 5 minutes, no caffeine for 30 minutes, empty bladder
- Take readings at the same time each day for consistent monitoring
- A single high reading doesn't mean hypertension — readings vary throughout the day
- Keep a log of readings to share with your doctor
- Both numbers matter — high diastolic pressure is just as concerning as high systolic
Questions people ask
- What is a normal blood pressure for my age?
- For adults of all ages, the recommended target is below 120/80 mmHg. Blood pressure naturally tends to rise with age, but this doesn't mean higher readings are acceptable — hypertension should be managed regardless of age.
- What does the top and bottom number mean?
- The systolic (top) number measures pressure when your heart beats. The diastolic (bottom) number measures pressure between beats when your heart rests. Both numbers are important for assessing cardiovascular risk.
- Can I lower blood pressure without medication?
- For elevated blood pressure and Stage 1 hypertension, lifestyle changes often help: regular exercise (150+ min/week), reducing sodium (under 2,300mg/day), limiting alcohol, quitting smoking, weight management, and stress reduction. Stage 2 typically requires medication.