Target Heart Rate Calculator

Use this target heart rate calculator to determine your maximum heart rate and target training zones (Zones 1 through 5) using the Karvonen method and Tanaka equation.

How to use this calculator

1. Enter your current age.
2. Enter your resting heart rate in beats per minute (best measured right after waking up).
3. Review your maximum heart rate (MHR) and 5 distinct training intensity zones.

Formula & method

Karvonen Heart Rate Reserve (HRR) Method

Target HR = ((Max HR − Resting HR) × %Intensity) + Resting HR

Max HR = 208 − (0.7 × Age) [Tanaka Equation]. HRR = Max HR − Resting HR.

Example

Age 30 (Max HR 187), Resting HR 60 → HRR = 127 bpm. Zone 2 (60–70%): 136 to 149 bpm.

Key insights

• Zone 2 (60–70% HRR) is the optimal endurance and fat-oxidation training zone for building mitochondrial density.
• The Karvonen formula accounts for resting heart rate, making it significantly more personalized than 220 minus age.
• Tanaka's equation (208 − 0.7 × age) provides superior MHR estimation for adults over 40.

How to interpret your result

Zone 2 (Endurance / Fat Burn)

Light aerobic pace where conversation is easy; builds base cardiovascular fitness.

Zone 4 (Anaerobic / Threshold)

Lactate threshold zone for improving high-intensity performance capacity.

Frequently asked questions

How do I find my resting heart rate?

Count your pulse for 60 seconds first thing in the morning before getting out of bed.

Why train in Zone 2?

Zone 2 training maximizes mitochondrial adaptation, fat burning, and aerobic efficiency without excessive recovery stress.

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