Peak HR Calculator
Use this tool to estimate your peak heart rate (maximum heart rate) and training zones for running, cycling, interval workouts, and general cardio planning.
What is peak HR?
Peak HR, often called maximum heart rate (HRmax), is the highest number of beats per minute your heart can reach during intense effort. A peak hr calculator gives you an estimate so you can organize training by effort rather than guessing.
Most people use this value to build heart rate zones for endurance training, fat-burning sessions, tempo work, HIIT, and recovery days.
How this peak hr calculator works
This calculator estimates your max heart rate using one of three common equations, then shows:
- Estimated peak HR
- Custom target range based on your selected intensity percentages
- Zone chart using both simple % of max and Karvonen (heart rate reserve) methods
Formulas included
- Tanaka: 208 − (0.7 × age)
- Fox: 220 − age
- Gellish: 207 − (0.7 × age)
No equation is perfect for every person. Treat these as starting points and adjust based on real-world training response, device data, and professional guidance if needed.
Why resting heart rate matters
When you enter resting HR, you unlock Karvonen-based zones. These can feel more personalized because they account for heart rate reserve (HRmax − resting HR), not just straight percentages of max HR.
For many athletes and regular exercisers, this gives more practical target ranges for easy runs, long rides, and threshold sessions.
How to use your results in training
Zone 1–2 (easy aerobic work)
Best for recovery, warm-ups, cool-downs, and building aerobic base. You should be able to hold a conversation.
Zone 3 (steady effort)
Useful for moderate continuous cardio. Breathing is stronger, but effort is still controlled.
Zone 4 (threshold)
Hard, sustainable effort for shorter intervals and tempo work. Great for improving performance capacity.
Zone 5 (near max)
Very hard intervals with full recovery between efforts. Use sparingly and with proper progression.
Important limitations
- Estimated peak HR is not a diagnosis or medical assessment.
- Heart rate can vary due to stress, heat, dehydration, caffeine, medications, and sleep.
- Wrist sensors can be less accurate than chest-strap monitors in high-intensity intervals.
- If you have cardiovascular risk factors or symptoms, speak with a licensed clinician before intense training.
Quick practical tips
- Recheck your resting HR after a calm morning and update the calculator.
- Use a consistent device and similar conditions when comparing workouts.
- Combine heart rate with pace, power, and perceived effort for better decisions.
- If your easy sessions constantly feel hard at zone targets, reduce intensity and reassess.
Bottom line
A peak hr calculator is one of the simplest tools for smarter cardio planning. It helps you train with intention, recover better, and avoid the common trap of doing every workout at the same intensity. Use it as a baseline, then refine with your own data and experience.