Heart Rate Zone Calculator
Calculate your 5 heart rate training zones from age and resting heart rate using the Karvonen Heart Rate Reserve formula.
Calculate Heart Rate Zones (HR_max = 220 − Age)
Enter your age and resting heart rate to compute verified training heart rate zones.
Calculation Results
Calculated using verified physical methodology: HR_{max} = 220 - \text{Age}
\text{Karvonen Zone: HR}_{target} = HR_{rest} + (HR_{reserve} \times \text{Zone\%})
Quick Summary
The Heart Rate Zone Calculator evaluates all 5 training heart rate zones from Zone 1 (Recovery) to Zone 5 (VO2 Max) using $HR_{\text{max}} = 220 - \text{Age}$ and the Karvonen Heart Rate Reserve formula for precision zone targeting.
Formula Explanation
Max HR: HR_{max} = 220 - \text{Age}
Karvonen Zone: HR_{target} = HR_{rest} + (HR_{reserve} \times \text{Zone\%})
HR_{reserve} = HR_{max} - HR_{rest}How It Works
The Heart Rate Zone Calculator estimates maximum heart rate ($HR_{\text{max}} = 220 - \text{age}$). Using the Karvonen method, it computes Heart Rate Reserve ($HRR = HR_{\text{max}} - HR_{\text{rest}}$). Each zone target ($HR_{\text{target}} = HR_{\text{rest}} + HRR \times \text{Zone\%}$) is then calculated for Zone 1 (50-60%) through Zone 5 (90-100%).
Step-by-Step Worked Example
Practical Problem: A 30-year-old runner with a resting heart rate of 60 bpm. Calculate all 5 heart rate training zones using the Karvonen method.
- Step 1: Max HR: $HR_{\text{max}} = 220 - 30 = \mathbf{190\text{ bpm}}$.
- Step 2: HR Reserve (HRR): $HRR = 190 - 60 = \mathbf{130\text{ bpm}}$.
- Step 3: Zone 1 (50-60%): $60 + (130 \times 0.50) = 125\text{ bpm}$ to $60 + (130 \times 0.60) = \mathbf{138\text{ bpm}}$ (Recovery).
- Step 4: Zone 3 (70-80%): $60 + (130 \times 0.70) = 151\text{ bpm}$ to $60 + (130 \times 0.80) = \mathbf{164\text{ bpm}}$ (Aerobic Threshold).
- Step 5: Zone 5 (90-100%): $60 + (130 \times 0.90) = 177\text{ bpm}$ to $\mathbf{190\text{ bpm}}$ (VO2 Max effort).
Real-World Calculation Examples
Scenario 1: 25-year-old Runner (HR rest 55 bpm)
Result: Max HR = 195 bpm. Zone 2: 138-153 bpm. Zone 4: 164-178 bpm. Youth runner zones.
Scenario 2: 40-year-old Recreational Runner (HR rest 65 bpm)
Result: Max HR = 180 bpm. Zone 2: 130-143 bpm. Zone 4: 155-167 bpm. Mid-age runner zones.
Scenario 3: 50-year-old Marathoner (HR rest 52 bpm)
Result: Max HR = 170 bpm. Zone 2: 111-126 bpm. Zone 3: 126-142 bpm. Masters marathoner.
Scenario 4: 60-year-old Cyclist (HR rest 58 bpm)
Result: Max HR = 160 bpm. Zone 2: 109-122 bpm. Zone 4: 135-147 bpm. Senior endurance athlete.
Key Benefits of Using This Calculator
Karvonen Precision Method
Uses the scientifically validated Karvonen Heart Rate Reserve formula for individualised zone targets.
All 5 Training Zones
Outputs Zones 1 to 5 covering recovery, aerobic base, tempo, lactate threshold, and VO2 Max efforts.
Dual Method Support
Supports both Karvonen HRR method and simple percentage of Max HR method.
100% Free & Client-Side
Executes locally in your browser with zero latency or web server transmission.
Frequently Asked Questions (FAQ)
What are the 5 heart rate training zones?
Zone 1 (50-60%): Recovery; Zone 2 (60-70%): Aerobic Base; Zone 3 (70-80%): Aerobic Threshold; Zone 4 (80-90%): Lactate Threshold; Zone 5 (90-100%): VO2 Max.
What is the Karvonen formula?
HR_target = HR_rest + (HR_reserve × Zone%). Developed by Finnish physiologist Martti Karvonen to provide more accurate individualised training zones.
How do I find my resting heart rate?
Measure it immediately upon waking before rising from bed, placing two fingers on your wrist pulse for 60 seconds, over 3 consecutive mornings and averaging the values.
Why is Zone 2 training important?
Zone 2 (60-70% max HR) training maximises mitochondrial density and fat oxidation efficiency — the aerobic base foundation for marathon and endurance performance.
What heart rate zone burns the most fat?
Zone 2 (60-70% max HR) burns the highest percentage of calories from fat, while Zone 4-5 burns the highest absolute number of calories per minute.
What is lactate threshold heart rate?
Lactate threshold typically occurs at approximately 80-90% max HR (Zone 4), where blood lactate production exceeds clearance rate.
How accurate is 220 minus age for max HR?
The 220-age formula has a standard deviation of ±10-12 bpm. A lab-conducted VO2 Max test provides a true measured max HR.
What heart rate zone should I train in for a marathon?
Marathon training: 80% of training in Zone 2, 15% in Zone 3, and 5% in Zone 4-5 (polarized training model).
Does fitness training lower resting heart rate?
Yes — endurance training typically lowers resting heart rate by 5-20 bpm. Elite marathon runners often have resting HRs of 35-50 bpm.
What is an unhealthy resting heart rate?
A resting heart rate above 100 bpm (tachycardia) or below 40 bpm (bradycardia) in non-athletes may require medical evaluation.