What is the Karvonen formula?

The Karvonen formula calculates target heart rate zones using your age and resting heart rate. Formula: Target HR = ((Max HR - Resting HR) x Intensity%) + Resting HR. Max HR is estimated as 220 minus your age. This method is more personalized than age-only formulas because it accounts for your fitness level through resting heart rate.

What are the heart rate training zones?

There are typically 5 heart rate zones: Zone 1 (50-60%) is very light activity for warm-up. Zone 2 (60-70%) is the fat burn zone for endurance. Zone 3 (70-80%) is the aerobic/cardio zone for cardiovascular fitness. Zone 4 (80-90%) is the anaerobic zone for performance. Zone 5 (90-100%) is the maximum effort zone for short bursts.

What is the fat burn heart rate zone?

The fat burn zone is typically 60-70% of your maximum heart rate (or 50-70% using Karvonen). At this intensity, your body uses a higher percentage of fat as fuel compared to carbohydrates. However, higher intensity zones burn more total calories and may result in greater overall fat loss.

How do I measure my resting heart rate?

Measure your resting heart rate first thing in the morning before getting out of bed. Place two fingers on the inside of your wrist or on the side of your neck. Count the number of beats in 60 seconds (or 30 seconds and multiply by 2). For most accurate results, measure for 3 consecutive mornings and take the average.

Target Heart Rate Calculator — Karvonen Formula

Calculate your personalized heart rate training zones using the Karvonen formula. Find fat burn, cardio, and peak zones with min/max BPM based on your age and resting heart rate. 100% private, no sign-up.

100% Private – your data never leaves this device.

Age (years)

Resting Heart Rate (BPM)

Measure first thing in the morning before getting out of bed. If unsure, use 65-72 BPM as a typical resting rate.

Max Heart Rate

BPM

Resting HR

BPM

Heart Rate Reserve

BPM

Age

years

Zone 1: Very Light (50-60%)

Warm-up, recovery, easy walking

0 - 0 BPM

Zone 2: Light / Fat Burn (60-70%)

Fat burning, endurance building, brisk walking

0 - 0 BPM

Zone 3: Moderate / Cardio (70-80%)

Aerobic fitness, improved circulation, running

0 - 0 BPM

Zone 4: Hard / Anaerobic (80-90%)

Performance training, speed work, interval training

0 - 0 BPM

Zone 5: Maximum (90-100%)

Maximum effort, sprints, high-intensity intervals

0 - 0 BPM

These zones use the Karvonen formula which accounts for your resting heart rate, making them more personalized than simple age-based estimates.

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Frequently Asked Questions

The Karvonen formula calculates target heart rate zones using your age and resting heart rate: Target HR = ((Max HR - Resting HR) x Intensity%) + Resting HR. Max HR = 220 - age. It is more personalized than age-only formulas.

Zone 1 (50-60%) is warm-up. Zone 2 (60-70%) is fat burn/endurance. Zone 3 (70-80%) is cardio/aerobic. Zone 4 (80-90%) is anaerobic/performance. Zone 5 (90-100%) is maximum effort/sprints.

The fat burn zone is 60-70% of max heart rate. At this intensity, your body uses more fat as fuel. However, higher intensity zones burn more total calories and may result in greater overall fat loss.

Measure first thing in the morning before getting out of bed. Place two fingers on your wrist or neck. Count beats in 60 seconds. For accuracy, measure for 3 mornings and average the results.

Last updated: June 2026

Target Heart Rate Calculator — Karvonen Formula

Zone 1: Very Light (50-60%)

Zone 2: Light / Fat Burn (60-70%)

Zone 3: Moderate / Cardio (70-80%)

Zone 4: Hard / Anaerobic (80-90%)

Zone 5: Maximum (90-100%)

What do you want to do next?

Frequently Asked Questions

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