Heart Rate Zones Calculator

Calculate your 5 personalized heart rate training zones based on age, resting heart rate, and maximum heart rate. Choose between the standard percentage method or the more accurate Karvonen (Heart Rate Reserve) method used by professional coaches.

Athlete Parameters

years
Measure morning pulse before getting out of bed.
BPM
Cardiovascular Thresholds
187BPM Max HR

Estimated via Tanaka equation: 208 − (0.7 × age).

Applied FormulaKarvonen HRR

Resting HR

65 BPM

HR Reserve

122 BPM

Zone 2 Target

138–150 BPM

Personalized Training Zones

Target Range (BPM)
Zone 1Recovery

Very light — warm-up, cool-down, active recovery

126–138

50%–60%

Zone 2Aerobic Base

Easy — fat burning, endurance building, conversational pace

138–150

60%–70%

Zone 3Tempo

Moderate — aerobic fitness, stamina improvement

150–163

70%–80%

Zone 4Threshold

Hard — lactate threshold, speed and power gains

163–175

80%–90%

Zone 5Maximum

All-out — VO₂max efforts, sprints, anaerobic capacity

175–187

90%–100%

Recommended Polarized 80/20 Weekly Volume

Zone 1–2 (Aerobic Base / Easy)
80%
Zone 3 (Tempo / Threshold Transition)
~5%
Zone 4–5 (VO₂max & Sprints)
~15%

Heart rate zones are population-derived physiological benchmarks with individual variation (±10–12 BPM). For precision sports prescription, consider pairing with blood lactate testing or a maximal VO₂ lab ramp test.

What Are Heart Rate Training Zones?

Heart rate training zones are intensity ranges defined as percentages of your maximum heart rate (MHR) or heart rate reserve (HRR). They categorize exercise intensity from very light (Zone 1) to all-out effort (Zone 5). Training in specific zones produces different physiological adaptations — fat oxidation, aerobic endurance, lactate threshold improvement, or VO₂max development.

1. Tanaka Maximum Heart Rate Formula
Max HR (BPM)=208−(0.7 × Age)
2. Karvonen Target Heart Rate Formula (HRR Method)
Target Zone HR=[ (Max HR − Resting HR) × % Intensity ]+Resting HR
Step-by-Step Calculation Breakdown (35 Years Old, Resting HR 62 BPM, Zone 2)
Step 1: Compute Maximum Heart Rate & Heart Rate Reserve (HRR)
Max HR = 208 − (0.7 × 35) = 183.5 BPM (≈ 184 BPM)
Heart Rate Reserve (HRR) = 184 − 62 = 122 BPM
Step 2: Calculate Zone 2 Boundary (60% to 70% of HRR)
Zone 2 Minimum = (122 × 0.60) + 62 = 73.2 + 62 = 135 BPM
Zone 2 Maximum = (122 × 0.70) + 62 = 85.4 + 62 = 147 BPM
Step 3: Target Zone 2 Aerobic Base Range
Zone 2 Heart Rate Range=135 – 147 BPM

The 5 Heart Rate Training Zones Explained

Zone 1: Recovery (50–60% Max HR)

Very light effort. Used for warm-ups, cool-downs, and active recovery between hard sessions. Promotes blood flow to aid muscle repair without adding training stress. Most daily activities fall in this zone. You should feel completely comfortable and able to sing while exercising here.

Zone 2: Aerobic Base (60–70% Max HR)

The foundation of endurance fitness. Zone 2 training improves mitochondrial density, fat oxidation capacity, and cardiovascular efficiency. Elite endurance athletes spend 70–80% of total training timein this zone. You should be able to maintain a full conversation. It feels “easy” — and that is the point. The adaptations happen at a cellular level over weeks and months of consistent Zone 2 work.

Zone 3: Tempo (70–80% Max HR)

Moderate effort sometimes called the “gray zone” or “no man's land” — too hard to be easy, too easy to produce the specific adaptations of Zones 4–5. Useful for marathoners training at goal race pace and for moderate-intensity fitness workouts. Conversation is possible but in short phrases. Limit time here unless it serves a specific training purpose.

Zone 4: Threshold (80–90% Max HR)

Hard effort near your lactate threshold — the intensity above which lactate accumulation begins to outpace clearance. Training here improves your body's ability to tolerate and clear lactate, raising the speed or power you can sustain for 20–60 minutes. Intervals of 4–20 minutes at Zone 4 are a cornerstone of performance-focused training plans.

Zone 5: Maximum (90–100% Max HR)

All-out effort targeting VO₂max — the maximum rate at which your body can consume oxygen. Sessions here last 30 seconds to 5 minutes (with full recovery between efforts). Zone 5 training improves anaerobic capacity, speed, and power. Due to the extreme stress, it should comprise no more than 5–10% of weekly training volume. Conversation is impossible.

Training Distribution: The 80/20 Rule

Research on elite endurance athletes consistently shows that the most effective training distribution is polarized: approximately 80% of training volume at low intensity (Zones 1–2) and 20% at high intensity (Zones 4–5), with minimal time in Zone 3. A 2014 study by Stöggl and Sperlich in Frontiers in Physiology found that polarized training produced greater improvements in VO₂max, time to exhaustion, and body composition than threshold-focused or high-intensity-only approaches.

Frequently Asked Questions

How accurate is the 220 minus age formula for max heart rate?
The '220 minus age' formula (Haskell & Fox, 1970) is a population average with a standard deviation of ±10–12 beats per minute. This means your true max heart rate could be up to 12 BPM higher or lower than the formula predicts. For more accuracy, the Tanaka formula (208 − 0.7 × age) is considered slightly better. The most accurate method is a supervised maximal exercise test performed by a health professional. If you know your actual max HR from testing, enter it manually in this calculator for precise zones.
What is Zone 2 training and why is it popular?
Zone 2 training (60–70% of max HR) is the intensity where your body primarily burns fat for fuel and develops aerobic base fitness. It has surged in popularity because research shows it improves mitochondrial function, cardiorespiratory fitness, and metabolic health more effectively than higher-intensity-only programs. Endurance athletes spend 70–80% of their total training volume in Zone 2. It feels easy — you should be able to hold a full conversation. For beginner runners, walking briskly or jogging very slowly often keeps you in Zone 2.
Is there really a 'fat-burning zone'?
Yes, but it is widely misunderstood. At lower intensities (Zone 2, roughly 60–70% max HR), a higher percentage of calories come from fat rather than carbohydrates. However, higher-intensity exercise burns more total calories per minute. A 2009 study by Carey (MSSE journal) found that the maximum rate of fat oxidation occurs at approximately 55–65% of VO₂max, which corresponds roughly to Zone 2. For weight loss, total calorie expenditure matters more than the fuel source — but Zone 2 is excellent for building fat-burning metabolic pathways.
What is the difference between the Karvonen and standard method?
The standard method calculates zones as simple percentages of your maximum heart rate (e.g., Zone 2 = 60–70% of max HR). The Karvonen method (also called Heart Rate Reserve method) subtracts your resting heart rate first — Zone HR = ((Max HR − Resting HR) × %Intensity) + Resting HR. The Karvonen method is more personalized because it accounts for your baseline fitness level. Someone with a low resting HR (e.g., 50 BPM) will get different zone boundaries than someone with a high resting HR (e.g., 80 BPM), reflecting real differences in cardiovascular fitness.
How do I measure my resting heart rate accurately?
Measure your resting heart rate first thing in the morning, before getting out of bed, on 3 consecutive days and take the average. Place two fingers on the inside of your wrist (radial pulse) and count beats for 60 seconds. Alternatively, use a pulse oximeter or a fitness tracker worn overnight. Avoid measuring after caffeine, alcohol, or intense exercise. A typical resting heart rate for adults is 60–100 BPM. Well-trained athletes often have resting rates of 40–60 BPM.
How long should I train in each heart rate zone?
The optimal distribution depends on your goals. The widely-used '80/20 rule' (polarized training) recommends 80% of training time in Zones 1–2 (easy) and 20% in Zones 4–5 (hard), with minimal time in Zone 3 ('no man's land'). For general fitness, aim for 150 minutes per week in Zone 2–3. For performance, elite runners and cyclists follow the polarized model. For weight management, a mix of Zone 2 (fat oxidation) and Zone 4 intervals (EPOC — excess post-exercise oxygen consumption) is effective.

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