Calculator form
Example data table
These example profiles show how different methods and resting pulse values can change the recommended training zone.
| Profile | Age | Resting HR | Method | Zone Model | Selected Range | Fat Burn Output |
|---|---|---|---|---|---|---|
| Steady jogger | 25 | 58 bpm | Tanaka | HRR | 60% to 70% | 136.2 to 149.2 bpm |
| Walking plan | 40 | 64 bpm | Traditional | % Max HR | 60% to 70% | 108.0 to 126.0 bpm |
| Cycle conditioning | 52 | 70 bpm | Gellish | HRR | 60% to 70% | 130.4 to 140.5 bpm |
Formula used
- Traditional maximum heart rate: Max HR = 220 - Age
- Tanaka maximum heart rate: Max HR = 208 - (0.7 × Age)
- Gellish maximum heart rate: Max HR = 207 - (0.7 × Age)
- Heart Rate Reserve: HRR = Max HR - Resting HR
- Fat burn zone using % Max HR: Target BPM = Max HR × Intensity%
- Fat burn zone using Karvonen: Target BPM = Resting HR + (HRR × Intensity%)
- Midpoint target: (Lower target + Upper target) ÷ 2
- Estimated calories per session: The calculator applies a heart-rate-based energy equation using age, body weight, workout duration, and either the live heart rate or the target midpoint.
How to use this calculator
- Enter your age, resting heart rate, body weight, and workout duration.
- Choose the maximum heart rate formula you want to trust.
- Select either the percentage model or the Karvonen method.
- Set your lower and upper intensity percentages for the desired fat burn zone.
- Add a live heart rate if you want a real-time comparison note.
- Click the calculate button to show your results above the form.
- Review the table, read the chart, and download the summary as CSV or PDF.
8 FAQs
1) What is a fat burn zone?
It is a heart-rate range often used for steady, moderate cardio. It usually sits below harder aerobic work and helps guide pacing for longer sessions.
2) Why does the Karvonen method give different numbers?
Karvonen uses your resting pulse, so it adapts the target to your current conditioning. That often makes the result more personalized than a simple percentage of maximum heart rate.
3) Which maximum heart rate formula should I choose?
Tanaka is a popular modern estimate. Traditional remains common for quick planning. Use a custom value when you already know your measured maximum from supervised testing.
4) Do I need a live heart rate to use this tool?
No. A live value is optional. If you leave it blank, the calculator still builds your target zone and uses the midpoint for calorie estimation.
5) Can I use this zone for interval training?
Yes, but intervals usually move above and below the fat burn range. This calculator is most useful for steady-state cardio pacing and recovery-aware planning.
6) Why is the calorie estimate only an estimate?
Calories vary with efficiency, body composition, medication, hydration, sensor accuracy, and exercise style. Treat the result as a planning guide, not a laboratory measurement.
7) How many weekly minutes should I aim for?
Many general fitness plans use about 150 minutes of moderate cardio weekly. Your ideal target can differ based on recovery, goals, and medical guidance.
8) Does training in this zone guarantee more fat loss?
Not by itself. Fat loss still depends on total energy balance, food intake, training consistency, sleep, and overall activity across the week.