Heart Rate Zone Calculator
Calculate your 5 training zones based on Max Heart Rate or Heart Rate Reserve (Karvonen).
Uses Heart Rate Reserve. More personalised — accounts for your resting heart rate.
💓 Heart Rate Zones — Karvonen (HRR)
Active recovery. Very easy effort. Fat metabolism dominant.
Conversational pace. Builds aerobic base and mitochondrial density.
Comfortably hard. Marathon race pace for most athletes.
Hard effort. Improves lactate clearance and speed endurance.
Maximum effort. Short intervals only. Develops peak aerobic power.
Why results differ between methods: Each method calculates zones differently. Karvonen personalises for your resting HR. HRmax% is what Garmin/Polar use. MAF targets aerobic base building. Polarized reflects research-backed 80/20 training distribution.
For most athletes: use Karvonen or HRmax% for general training. Polarized if following a structured endurance plan.
Understanding the 5 Zones
Heart Rate training is about targeting specific physiological adaptations. 1. Zone 1 (Recovery): < 60%. Promotes blood flow and active recovery. 2. Zone 2 (Endurance Base): 60 - 70%. The "Fat Burning" zone. Builds mitochondrial density and capillary networks. You should be able to speak in full sentences. 3. Zone 3 (Tempo / Grey Zone): 70 - 80%. Often called "junk miles" because it's too hard for recovery but too easy for threshold gains. 4. Zone 4 (Threshold): 80 - 90%. Improves your ability to clear lactate. "Comfortably hard." 5. Zone 5 (VO2 Max): 90 - 100%. Peak aerobic capacity. Can only be held for a few minutes.💓 Heart Rate Training Zones
| Zone | Intensity (%) | Feeling | Benefit |
|---|---|---|---|
| Zone 1 | 50 - 60% | Very Easy | Recovery, Warm-up |
| Zone 2** | **60 - 70%** | **Conversational** | **Base Building, Fat Burn |
| Zone 3 | 70 - 80% | Moderate | Aerobic Capacity (Grey Zone) |
| Zone 4 | 80 - 90% | Hard | Lactate Threshold |
| Zone 5 | 90 - 100% | Maximum | VO2 Max, Anaerobic Speed |
🧮 Max HR vs. Heart Rate Reserve (Karvonen)
* Simple Max HR:220 - Age. Often inaccurate.
* Karvonen Formula**: Uses your **Resting Heart Rate (RHR) to determine your "reserve."
* *Formula*: (MaxHR - RHR) * % Intensity + RHR
* *Verdict*: Much more accurate for trained individuals.The 80/20 Rule
Elite endurance athletes spend 80% of their time in Zone 2** and only **20% in Zone 4/5. Spending too much time in Zone 3 leads to stagnation and burnout.Use Cases / Example Scenarios
Clinical precision. My exercise numbers have exploded since I started following these percentages.
The Heart Rate Zone Calculator strategy at 30:00 pace is bold but scientifically sound. It worked for my last race.
Used this for my Heart Rate Zone Calculator training. The split at 30:00 was exactly what I needed to finish strong.
These scenarios are illustrative examples based on typical use cases.
WinSport Editorial & Research Standards
"All formulas and reference values used in this tool are sourced from peer-reviewed scientific literature and validated clinical guidelines. Our research team continuously audits each calculator for accuracy and updates methodology as new evidence emerges."
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