Find your maximum heart rate and 5 personalized training zones instantly. Optionally use the Karvonen formula with your resting heart rate for even greater accuracy.
| Zone | % Max HR | BPM Range | Purpose |
|---|
| Zone | % HRR | BPM Range | Purpose |
|---|
Warm-up and active recovery. Very comfortable, you can hold a full conversation. Improves circulation and helps muscles recover between harder sessions.
The fat-burning zone. Your body uses primarily fat for fuel. Ideal for long, steady-state cardio sessions and building your aerobic endurance base.
Aerobic conditioning. Breathing becomes heavier but you can still speak in short sentences. Builds cardiovascular efficiency and improves overall fitness.
Anaerobic threshold and race pace. You can only speak a word or two. Increases lactate threshold, speed, and high-intensity endurance.
All-out effort. Sprints and HIIT. Can only be sustained for very short bursts. Maximizes speed, power output, and VO2 max. Not for beginners.
Enter your age and press Calculate Heart Rate Zones. The calculator immediately shows your estimated maximum heart rate using the 220 − age formula, along with a full breakdown of all five training zones in beats per minute.
For greater accuracy, also enter your resting heart rate — the number of times your heart beats per minute when you are completely at rest, typically measured first thing in the morning before getting out of bed. With your resting HR, the calculator applies the Karvonen formula, which accounts for your current fitness level and produces personalized zones that are more precise than the simple percentage method.
The formula Max HR = 220 − age was popularized in the early 1970s and remains the most widely used estimate because it requires no equipment and no effort test. A 25-year-old has an estimated maximum of 195 bpm; a 50-year-old, 170 bpm.
It is worth understanding that this is a population average formula, not an individual measurement. Individual maximum heart rates can vary by ±10–20 bpm from the predicted value. Athletes who want precise zones can determine their true maximum heart rate through a medically supervised or field-based maximal effort test. For the vast majority of exercisers, however, the 220 − age estimate is sufficiently accurate for structuring effective training.
Other formulas exist — Tanaka (208 − 0.7 × age) is slightly better for older adults, and Fox's formula (220 − age) remains the most accessible. This calculator uses the classic 220 − age formula because it is the most universally understood and referenced.
Finnish sports scientist M.J. Karvonen developed a refined method in the 1950s that incorporates your heart rate reserve (HRR) — the range between your resting heart rate and your maximum heart rate. The formula is:
Target HR = ((Max HR − Resting HR) × Intensity %) + Resting HR
For example, consider a 35-year-old with a resting heart rate of 55 bpm. Their max HR is 185 bpm. For Zone 2 at 65% intensity: ((185 − 55) × 0.65) + 55 = 84.5 + 55 = 139.5 bpm. Without the Karvonen adjustment, Zone 2 at 65% of max HR alone would be 120 bpm — a meaningful 19 bpm difference that can affect training outcomes.
The Karvonen method rewards good fitness: as your resting heart rate decreases through consistent aerobic training, your training zones shift upward. This means a fit individual and an unfit individual of the same age may train at noticeably different absolute heart rates even within the same relative zone.
Zone 2 (60–70% max HR) is often called the "fat-burning zone" because the body's primary energy substrate at this intensity is fat rather than carbohydrate. While total calorie expenditure is lower than at higher intensities, the proportion of calories from fat is highest in Zone 2. For weight management, long steady-state sessions at 60–70% max HR — think brisk walking, easy cycling, or a comfortable jog — are sustainable enough to accumulate significant training volume.
That said, higher-intensity training (Zones 3–5) burns more total calories per minute, which also contributes to fat loss. An optimal program combines Zone 2 base work with some higher-intensity sessions for maximum metabolic benefit.
Regular exercise in Zones 2 and 3 improves heart efficiency, lowers resting heart rate over time, and reduces the risk of cardiovascular disease, hypertension, and type 2 diabetes. The American Heart Association recommends at least 150 minutes per week of moderate-intensity aerobic activity (roughly Zone 2–3) for adults.
Serious athletes use all five zones strategically. Zone 2 builds the aerobic base; Zone 4 raises the lactate threshold (the point at which lactate accumulates faster than the body can clear it, causing the "burn"); Zone 5 intervals improve VO2 max and speed. A polarized training model — roughly 80% of sessions in Zones 1–2 and 20% in Zones 4–5 — is supported by research as highly effective for endurance sport performance.
Resting heart rate (RHR) is measured in beats per minute when you are completely at rest — ideally lying still for 5 minutes upon waking. For most healthy adults, RHR falls between 60 and 100 bpm. A lower resting heart rate generally indicates a more efficient cardiovascular system. Endurance athletes commonly have resting heart rates of 40–55 bpm.
Tracking your resting heart rate over weeks and months is also a useful indicator of recovery and overtraining. A RHR that is 5–10 bpm higher than normal often signals that your body needs more rest, or that illness is developing. A fitness tracking app like Brite can help you log your RHR daily alongside your workouts to spot these trends.
For serious training, a chest strap or quality sports watch gives the most reliable real-time data, allowing you to stay precisely within a target zone throughout your workout.
Log your training sessions, monitor resting heart rate trends, and build consistent fitness habits with Brite — the all-in-one health and habit tracker.
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