Health and Fitness / Free Tools
Free Heart Rate Zone Calculator Online
Use this free heart rate zone calculator to find your five training zones based on your age and, optionally, your resting heart rate for a more personalized result. It works as a general cardio training calculator for running, cycling, or any heart-rate-based workout - no sign-up required.
What is a heart rate zone calculator and why it matters
A heart rate zone calculator divides your heart rate range into five training zones, from very light to maximum effort, based on a percentage of your maximum heart rate. This matters because training in a specific zone - whether for fat burning, building aerobic base, or improving performance - is far more effective than guessing intensity by feel alone. Elite and recreational athletes both use zone training to make sure easy days stay easy and hard days are actually hard enough to drive improvement.
How this calculator works
This tool first estimates your maximum heart rate using either the simple formula (220 minus your age) or, if you provide your resting heart rate, the more personalized Karvonen method, which factors in your heart rate reserve (the gap between resting and maximum heart rate). It then calculates five zones as percentages of that maximum, each corresponding to a different training intensity and purpose, from recovery to maximum effort.
Common searches this calculator answers
- What is my maximum heart rate?
- What heart rate zone should I train in to burn fat?
- How do I calculate my heart rate zones by age?
- What is the Karvonen method for heart rate training?
- What heart rate zone is best for cardio endurance?
How to use it
- Enter your age.
- Choose the simple method, or select Karvonen and enter your resting heart rate for a more personalized result.
- If using Karvonen, measure your resting heart rate first thing in the morning before getting out of bed for the most accurate reading.
- Click Calculate heart rate zones.
- Read your five training zones and match your workout intensity to your goal.
Heart rate zone reference
| Zone | % of max HR | Purpose |
|---|---|---|
| Zone 1 - Very light | 50-60% | Warm-up, recovery, active rest |
| Zone 2 - Light | 60-70% | Fat burning, aerobic base building |
| Zone 3 - Moderate | 70-80% | Cardio fitness, aerobic endurance |
| Zone 4 - Hard | 80-90% | Improving performance and speed |
| Zone 5 - Maximum | 90-100% | Peak effort, short high-intensity bursts |
Tips
- Most endurance training should happen in Zone 2, with only a smaller portion of weekly training in Zones 4 and 5 - this is often called polarized training.
- Use a chest strap or reliable wrist-based heart rate monitor for accurate real-time readings during exercise, since perceived effort alone can be misleading.
- Resting heart rate tends to improve (get lower) as cardiovascular fitness improves - re-check your zones every few months.
- The simple age-based formula is a reasonable starting point, but the Karvonen method is generally more accurate since it accounts for your individual fitness level.
Frequently asked questions
Is this heart rate zone calculator free to use?
Yes. It is completely free, works in your browser, and does not require any sign-up or download.
Which method is more accurate, simple or Karvonen?
The Karvonen method is generally considered more accurate because it accounts for your resting heart rate and heart rate reserve, rather than relying on age alone.
What zone should I train in to lose weight?
Zone 2 is often associated with fat burning since a higher percentage of energy at that intensity comes from fat. However, total calories burned across all zones also matters for weight loss, not just the fuel source used.
Why is my actual max heart rate different from the formula?
Age-based formulas are population averages, so individual max heart rate can vary by 10-15 bpm or more. A supervised max heart rate test provides the most accurate individual number.
How do I measure my resting heart rate accurately?
Measure it first thing in the morning, before getting out of bed, ideally for a full 60 seconds using a heart rate monitor or by counting your pulse.