📖 Overview
Use this tool to select a practical heart rate target for cardio sessions.
🧪 Example Scenarios
Use these default and higher-pressure example inputs to explore how sensitive this calculator is before using your real numbers.
| Input | Base Case | Higher Pressure Case |
|---|---|---|
| Age (years) | 32 | 36.8 |
| Intensity (%) | 75 | 90 |
⚙️ How It Works
This uses an age-based max heart-rate estimate and applies your target intensity percentage.
The Formula
THR = (220 − Age) × (Intensity% ÷ 100)
| THR | Target Heart Rate in beats per minute (bpm) |
| 220 − Age | Estimated maximum heart rate (Fox formula) |
| Intensity | Target training intensity as a percentage |
💡This calculator is scenario-based. Better input quality leads to better decision quality.
Quick Reference
| Training Zone | Intensity | Purpose |
|---|---|---|
| Recovery | 50–60% | Active recovery, very light effort |
| Fat Burn | 60–70% | Aerobic base, fat oxidation, long sessions |
| Aerobic | 70–80% | Endurance, cardiovascular fitness improvement |
| Threshold | 80–90% | Performance, lactate threshold training |
| VO₂ Max | 90–100% | High intensity, short bursts, race prep |
When To Use This
- Use this tool when you need a fast decision during active planning or execution.
- Use this before committing money, time, or tradeoffs that are hard to reverse.
- Use this to compare options using the same assumptions across scenarios.
Edge Cases To Watch
- Results can be misleading if key inputs are missing, stale, or unrealistic.
- Very small or very large values may amplify rounding effects and interpretation risk.
- If assumptions change mid-decision, recalculate before acting.
Practical Tips
💡 Use ranges for training zones, not one exact number.
💡 Adjust by perceived effort and recovery quality.
💡 Recalculate as age or training goals change.
Frequently Asked Questions
❓ Is 220-age exact?
No, it is a planning heuristic.
❓ Should beginners use lower intensity?
Usually yes, especially when building aerobic base.