Target Heart Rate Calculator
Calculate your personalised target heart rate zone for exercise using the Karvonen or percentage method. Optimise fat burn, cardio fitness, or peak performance.
Calculate Target Heart Rate
Why Exercising by Heart Rate Changes Everything
Most people have two exercise speeds: too easy or too hard. They walk for an hour and wonder why nothing changes, or they sprint until they can't breathe and quit after two weeks. The sweet spot — the intensity that actually produces results — requires precision. That's what target heart rate gives you.
Your target heart rate is the range where exercise is intense enough to trigger adaptation but sustainable enough to maintain for the duration of your workout. Think of it like the rev range in a car — too low and you're wasting fuel going nowhere, too high and you'll blow the engine.
The right target zone depends on your goal. Fat loss, cardiovascular fitness, and race performance all happen at different intensities. Training in the wrong zone isn't dangerous, but it's inefficient — and most people don't have unlimited time to exercise.
Target Heart Rate by Fitness Goal
These ranges use percentage of heart rate reserve (Karvonen method) for greater accuracy. Your actual bpm targets depend on your age and resting heart rate — use the calculator above to find yours.
| Goal | % Heart Rate Reserve | Session Duration | Weekly Frequency |
|---|---|---|---|
| Weight loss (beginner) | 40–60% | 30–60 min | 3–5 days |
| Fat burning (experienced) | 60–70% | 45–90 min | 4–6 days |
| General fitness | 60–80% | 30–60 min | 3–5 days |
| Race training | 70–85% | 20–60 min | 3–4 days |
| Peak performance | 85–95% | Intervals: 2–5 min | 1–2 days |
What this means for you: If you're exercising for general health and fitness, the 60–80% range covers most of what you need. Spend 80% of your training at the lower end and 20% at the higher end. This "polarised" approach — endorsed by sports science and used by elite endurance athletes — produces better results than training at a moderate intensity every session.
Resting Heart Rate: Your Hidden Fitness Score
Your resting heart rate isn't just a number for the Karvonen formula — it's one of the most reliable indicators of cardiovascular health. A lower resting HR means your heart pumps more blood per beat, so it doesn't need to work as hard at rest.
| Resting HR (bpm) | Fitness Level | What It Means |
|---|---|---|
| <50 | Athlete | Highly trained cardiovascular system |
| 50–60 | Excellent | Very fit, regular exerciser |
| 60–70 | Good | Above average fitness |
| 70–80 | Average | Typical for sedentary adults |
| 80–100 | Below average | Could improve with regular exercise |
| >100 | See a doctor | May indicate an underlying condition |
How to measure it: Take your pulse first thing in the morning, before getting out of bed, on 3 consecutive days. Average the results. Don't measure after caffeine, alcohol, or a poor night's sleep — these artificially elevate your reading.
Max Heart Rate: Why 220 Minus Age Is Wrong
The "220 minus age" formula was never based on original research — it was derived from a rough estimate in the 1970s that got repeated until everyone assumed it was fact. It can be off by 10–20 bpm in either direction. For a 40-year-old, that's the difference between a max of 160 and 180 — which changes every zone dramatically.
This calculator uses the Tanaka formula (208 − 0.7 x age), published in the Journal of the American College of Cardiology in 2001. It's more accurate across all age groups, though still an estimate. The only way to know your true max HR is a graded exercise test — either supervised by a cardiologist or as a field test (see our Heart Rate Zone Calculator for the protocol).
If you own a heart rate monitor and regularly push yourself during exercise, your highest recorded heart rate during an all-out effort is likely close to your true max. Use the "Custom Max HR" field above to enter a known value.
Common Mistakes When Using Heart Rate Targets
Using the Wrong Max HR
The 220 − age formula can be off by 10–20 bpm. If possible, use the Tanaka formula or a field test. Wrong max HR means wrong zones — and wrong zones mean wasted training.
Ignoring Resting HR Changes
As you get fitter, your resting HR drops — which changes your Karvonen zones. Retest every 4–6 weeks. An athlete with a resting HR of 50 has very different zones than a beginner at 80 bpm.
Training Too Hard, Too Often
Going all-out every session feels productive but leads to overtraining, fatigue, and injury. The 80/20 rule: 80% of sessions at conversational pace (Zones 1–2), 20% at high intensity (Zones 4–5).
Not Accounting for External Factors
Heat, humidity, caffeine, stress, sleep, and dehydration all raise heart rate at a given effort level. If your HR seems high relative to effort, it's a sign to back off, not push harder.
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How to use this tool
Enter your age
Enter your resting heart rate (optional but recommended)
Choose the calculation method
Common uses
- Finding your ideal exercise intensity for fat loss
- Setting heart rate targets for cardio training
- Monitoring workout intensity with a heart rate monitor
- Adjusting training zones as fitness improves
- Comparing Karvonen and percentage calculation methods
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