Stax

Heart Rate Zone Calculator

Calculate 5 heart rate training zones using the Karvonen formula.

Default: 220 − age

Max HR
190 BPM
Resting HR
60 BPM
HR Reserve
130 BPM
Method
Karvonen
Zone 1 — Warm Up50–60%
Very light intensity. Improves base fitness and recovery.
125–138
BPM
Zone 2 — Fat Burn60–70%
Light intensity. Optimal fat burning zone for weight loss.
138–151
BPM
Zone 3 — Aerobic70–80%
Moderate intensity. Improves cardiovascular endurance.
151–164
BPM
Zone 4 — Anaerobic80–90%
Hard intensity. Builds speed and performance.
164–177
BPM
Zone 5 — Maximum90–100%
Maximum effort. Short bursts for peak performance.
177–190
BPM

Enter your current BPM to see which zone you're in

Train smarter with heart rate zones

Knowing your target heart rate zones helps you train at the right intensity for your goal — whether that's burning fat, building aerobic capacity, or improving speed. This calculator supports both the Karvonen formula (more personalised) and simple % of max HR.

Karvonen vs % of Max HR

The Karvonen method uses your Heart Rate Reserve (Max HR − Resting HR) which accounts for your fitness level. A trained athlete with a low resting HR gets higher zone targets than a sedentary person of the same age — which is more accurate for personalised training.

Frequently asked questions

What are heart rate training zones?
Heart rate zones are ranges of beats per minute that correspond to different exercise intensities. Zone 1 (50–60%) is easy warm-up; Zone 5 (90–100%) is maximum effort. Training in specific zones achieves different fitness goals.
What is the Karvonen formula?
The Karvonen formula calculates heart rate zones using your Heart Rate Reserve (HRR = Max HR − Resting HR). Zone BPM = Resting HR + HRR × Zone%. It is more accurate than simple % of max HR because it accounts for individual fitness level.
How is maximum heart rate estimated?
The default formula is Max HR = 220 − age. This is an estimate — actual max HR varies by individual. For more accuracy, measure your max HR during a graded exercise test or enter a custom value.
What is the fat burn zone?
Zone 2 (60–70% of max HR) is often called the fat burn zone because a higher proportion of calories burned comes from fat at this intensity. However, total calorie burn is lower than at higher intensities.
Which zone should I train in?
It depends on your goal: Zone 1–2 for recovery and fat loss, Zone 3 for aerobic endurance, Zone 4 for speed and performance, Zone 5 for peak power. Most training plans recommend spending the majority of time in Zones 2–3.

Related tools