Heart Rate Training Zones Calculator
Find your personalized cardio training zones using the Karvonen formula.
Tip: measure resting heart rate first thing in the morning, before getting out of bed.
What Is the Heart Rate Training Zones Calculator?
Heart Rate Training Zones Calculator Formula
Max HR = 220 − Age
Target HR = Resting HR + Intensity% × (Max HR − Resting HR)
How Is the Heart Rate Training Zones Calculator Calculated?
The Karvonen formula uses your Heart Rate Reserve (HRR) — the gap between your max heart rate and resting heart rate — instead of just a percentage of max heart rate. Because it accounts for your resting heart rate, it adjusts to your actual fitness level rather than treating everyone the same age as identical.
Heart Rate Training Zones Calculator Example
A 30-year-old with a resting heart rate of 65 bpm has a Max HR of 190 bpm and an HRR of 125 bpm. Their Zone 3 (Moderate, 70-80%) range is 153–165 bpm.
How to Use the Heart Rate Training Zones Calculator
Step 1
Enter your age.
Step 2
Enter your resting heart rate, ideally measured first thing in the morning.
Step 3
Review your five training zones, each with a target bpm range.
Benefits
- More personalized than flat percentage-of-max-HR charts, since it accounts for your resting heart rate.
- Breaks training into five clear zones so you can match effort to your workout goal.
- Useful for any cardio activity — running, cycling, swimming, or general fitness training.
Common Heart Rate Training Zones Calculator Scenarios
Scenario 1
Structuring interval training around specific heart rate zones.
Scenario 2
Making sure recovery or warm-up sessions stay in Zone 1-2 instead of overtraining.
Scenario 3
Pairing with a heart rate monitor or fitness tracker during workouts.
Understanding Your Result
Each zone represents a different training intensity. Lower zones (1-2) build aerobic endurance and burn a higher percentage of fat, while higher zones (4-5) build anaerobic capacity and speed but can only be sustained briefly.
Tips
- Most endurance training should happen in Zone 2, with only a small portion of weekly training in Zone 4-5.
- Re-check your resting heart rate every few weeks — it tends to drop as cardiovascular fitness improves.
- Use a chest-strap or wrist heart rate monitor for the most accurate real-time zone tracking.
Common Mistakes
- Using age-predicted max HR (220 − age) as an exact number — it's a population average and can be off by 10-15 bpm for any individual.
- Training mostly in Zone 4-5, which builds fatigue faster than fitness for most endurance goals.
- Measuring resting heart rate after caffeine, stress, or activity instead of at rest.
Frequently Asked Questions
What is the Karvonen formula?
It's a method for calculating target heart rate training zones that uses heart rate reserve (max HR minus resting HR) rather than just a percentage of max heart rate.
Which zone should I train in to lose fat?
Zone 2 (60-70% of heart rate reserve) is typically the most efficient for sustained fat burning and aerobic base building.
Is the 220 minus age formula accurate?
It's a widely used estimate, but individual max heart rate can vary by 10-15 bpm from this formula — a lab or field fitness test gives a more precise number.
How do I measure my resting heart rate?
Check your pulse for 60 seconds immediately after waking up, before getting out of bed, for the most accurate resting reading.
What are the five heart rate training zones?
Zone 1 (50-60%, very light/recovery), Zone 2 (60-70%, fat-burning/aerobic base), Zone 3 (70-80%, moderate aerobic), Zone 4 (80-90%, hard/anaerobic), and Zone 5 (90-100%, maximum effort).
How is the Karvonen formula different from just using 220 minus my age?
220 minus age only gives an estimated max heart rate. Karvonen also factors in your resting heart rate to calculate Heart Rate Reserve, which personalizes the zones to your actual fitness level rather than just your age.
Do I need a heart rate monitor to use these zones?
It's not required, but it's recommended for accuracy during real workouts — perceived effort alone is a rough substitute for an actual heart rate reading.
Should athletes use a more precise method than this formula?
Some coaches use lab-tested max heart rate and lactate threshold testing for more precision, though Karvonen with an accurately measured resting heart rate is a solid estimate without lab equipment.
Can medications affect my heart rate zones?
Yes — beta-blockers and some other heart medications can significantly lower both resting and max heart rate, making standard formulas inaccurate. Consult a doctor if you're on such medication.
Important Information
This tool provides general fitness estimates and is not a substitute for guidance from a doctor or certified trainer, especially if you have a heart condition.
Last updated: July 26, 2026