Target Heart Rate Calculator
Find your heart-rate training zones from age and resting heart rate, using the more personalized Karvonen method.
| Zone | Intensity | Heart rate (bpm) |
|---|
The Karvonen formula
Heart rate reserve (HRR) = Max HR − Resting HR
Target = (HRR × intensity%) + Resting HR
Age 30, resting 65: Max HR = 190, HRR = 125. A 70% target = 125 × 0.70 + 65 = ~153 bpm.
Age 55, resting heart rate 50 bpm (low, typical of a well-conditioned endurance athlete). Max HR = 220 − 55 = 165 bpm. HRR = 165 − 50 = 115 bpm.
Karvonen 70% target: 115 × 0.70 + 50 = 80.5 + 50 ≈ 131 bpm. The simple method (just 70% of max HR, ignoring resting rate) gives 165 × 0.70 ≈ 116 bpm instead — a 15 bpm gap. Because this person's resting heart rate is unusually low, Karvonen credits their fitness level and sets a higher, more demanding target than the simple method would; for someone with an average resting rate around 70, the two methods land much closer together.
Training zones and what they're for
| Zone | % of reserve | Use |
|---|---|---|
| Warm-up | 50–60% | Recovery, easy movement |
| Fat burn | 60–70% | Base endurance, long efforts |
| Cardio / aerobic | 70–80% | Fitness and stamina gains |
| Anaerobic | 80–90% | Speed and performance |
| Peak / max | 90–100% | Short intervals only |
Most cardiovascular benefit comes from the aerobic zones (60–80%). The "fat burn" label is a bit misleading — you burn a higher percentage of fat at low intensity, but more total fat at higher intensity, so for weight loss total calories burned matter most. The 220−age formula is a rough average (±10–12 bpm), so use perceived effort and a chest-strap monitor to fine-tune. Pace your runs alongside this with the pace calculator.
Moderate-intensity zone by age (resting HR 70)
| Age | Max HR | Moderate zone (50–70%) |
|---|---|---|
| 20 | 200 | 135–161 bpm |
| 30 | 190 | 130–154 bpm |
| 40 | 180 | 125–147 bpm |
| 50 | 170 | 120–140 bpm |
| 60 | 160 | 115–133 bpm |
| 70 | 150 | 110–126 bpm |
These assume a resting heart rate of 70 bpm — a common average — so use the calculator above with your own resting rate for a more personal number, especially if it's notably higher or lower than 70.
Common target heart rate mistakes
- Treating 220 − age as exact. It's a population average with roughly ±10–12 bpm of individual variation, not a lab-measured personal max.
- Using the simple %-of-max method and expecting it to match Karvonen. As the athlete example above shows, the two methods can diverge by 10–15 bpm for someone with an unusually low or high resting heart rate.
- Never re-measuring resting heart rate. It tends to drop as fitness improves, which shifts every Karvonen zone even though max heart rate itself hasn't changed.
Frequently asked questions
What is my target heart rate?
Moderate: 50–70% of max; vigorous: 70–85%. A 30-year-old's moderate zone ≈ 95–133 bpm.
What is the Karvonen method?
Target = (HR reserve × intensity) + resting HR — personalized by your resting rate.
Which zone burns the most fat?
Low intensity burns a higher fat percentage, but higher intensity burns more total fat. Total calories win.
How does Karvonen differ from a simple % of max heart rate?
Karvonen factors in resting heart rate, so a well-trained person with a low resting rate gets a higher, more personalized target — the gap can be 10-15 bpm versus the simple method.
Does resting heart rate change over time?
Yes — it often drops as fitness improves, sometimes by 10 bpm or more, so re-measuring it periodically keeps your zones accurate.
Related calculators
Medical disclaimer: Estimated zones for general fitness, not medical advice. If you have a heart condition or take medication affecting heart rate, consult a doctor before intense exercise. Formula: Karvonen method. Last reviewed: September 2026.