How to Use This Calculator
1. Enter Your Age
Your age helps estimate your maximum heart rate (Max HR) — the highest your heart can beat during intense effort.
2. Add Your Resting Heart Rate (Optional)
Measure first thing in the morning or after sitting quietly for 5 minutes. Entering this makes your zones more personalized using the Karvonen (HRR) method. If you don’t know it, just leave blank.
3. Choose a Formula
- Tanaka (default):
208 − 0.7 × age. More accurate for adults over 50. - Fox (classic):
220 − age. The traditional formula, still widely used.
4. Choose a Method
- HRR (Karvonen): Uses Max HR and Resting HR for tailored results. Best if you know your resting HR.
- % of Max HR: Simpler method if you don’t know resting HR. Less precise, but still useful.
5. View Your Intensity Zones
The calculator shows three exercise zones recommended by Physio Ed.:
- Light (55–65%): Gentle pace. Perfect for warm-ups, cool-downs, or recovery days.
- Moderate (65–75%): Comfortable challenge. Ideal for most weekly sessions.
- Vigorous (75–85%): Challenging effort. Use if medically cleared and build gradually.
6. Apply It to Your Workouts
Use zones as a guide alongside how you feel:
- At moderate effort you should speak short sentences.
- At vigorous effort you may only manage a few words