# Heart Rate Zones Calculator (Karvonen Method)

Calculate your 5 heart rate training zones using the Karvonen method. Find your optimal heart rate for fat burning, cardio, and high-intensity training.

## What this calculates

Training in the right heart rate zone is key to achieving specific fitness goals, whether you want to burn fat, build endurance, or improve speed. This calculator uses the Karvonen method, which factors in your resting heart rate for more personalized zones than simple percentage-of-max methods.

## Inputs

- **Age** (years) — min 10, max 100
- **Resting Heart Rate** (bpm) — min 30, max 120 — Measure first thing in the morning before getting out of bed

## Outputs

- **Maximum Heart Rate** — Estimated maximum heart rate (220 – age)
- **Heart Rate Reserve** — Difference between max HR and resting HR
- **Zone 1 – Warm-up (50–60%)** — formatted as text — Very light activity, recovery
- **Zone 2 – Fat Burn (60–70%)** — formatted as text — Light aerobic, fat burning, endurance base
- **Zone 3 – Aerobic (70–80%)** — formatted as text — Moderate intensity, cardiovascular fitness
- **Zone 4 – Anaerobic (80–90%)** — formatted as text — High intensity, speed and power training
- **Zone 5 – Max Effort (90–100%)** — formatted as text — Maximum effort, short bursts only

## Details

The Karvonen method calculates Target Heart Rate (THR) using the formula: THR = ((Max HR – Resting HR) × % Intensity) + Resting HR. Maximum heart rate is estimated as 220 minus your age (Fox formula). The five training zones are: Zone 1 (50–60%) for warm-up and recovery; Zone 2 (60–70%) for fat burning and endurance base building; Zone 3 (70–80%) for aerobic fitness and cardiovascular improvement; Zone 4 (80–90%) for anaerobic threshold and speed work; Zone 5 (90–100%) for maximum effort sprints. Most people benefit most from spending the majority of training time in Zones 2–3.

## Frequently Asked Questions

**Q: How do I measure my resting heart rate?**

A: Measure your resting heart rate first thing in the morning before getting out of bed. Place two fingers on your wrist (radial artery) or neck (carotid artery), count the beats for 60 seconds, or count for 15 seconds and multiply by 4. Take the average over 3–5 days for accuracy.

**Q: Is the 220 minus age formula accurate?**

A: The 220 minus age formula (Fox formula) is a widely-used estimate, but individual max heart rates can vary by 10―20 bpm. For a more accurate maximum heart rate, consider a graded exercise test supervised by a healthcare professional. Some people use the Tanaka formula (208 – 0.7 × age) as an alternative.

**Q: Which heart rate zone is best for weight loss?**

A: While Zone 2 (60–70%) burns the highest percentage of calories from fat, total calorie burn is more important for weight loss. Higher-intensity zones (3–4) burn more total calories per minute. A mix of zone 2 endurance work and higher-intensity intervals is generally most effective for fat loss.

**Q: Should I consult a doctor before training based on heart rate?**

A: Yes, especially if you are over 40, have a history of heart disease, high blood pressure, chest pain, dizziness during exercise, or any other cardiovascular concerns. A healthcare provider can help determine safe training intensities for your individual situation.

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Source: https://vastcalc.com/calculators/health/heart-rate
Category: Health & Fitness
Last updated: 2026-04-21