How do I calculate my target heart rate?

Target heart rate = (Max HR − Resting HR) × intensity% + Resting HR. This is the Karvonen formula. Your max HR is estimated as 220 minus your age (Fox formula) or 208 − 0.7 × age (Tanaka formula, more accurate). For moderate exercise, target 50–70% of max HR. For vigorous exercise, target 70–85%.

What is Zone 2 heart rate by age?

Zone 2 is 60–70% of your max heart rate. For a 30-year-old (max HR 190), Zone 2 is 114–133 bpm. For a 40-year-old (max HR 180), it is 108–126 bpm. For a 50-year-old (max HR 170), it is 102–119 bpm. Zone 2 is the optimal range for fat burning and building aerobic endurance.

What is the formula for max heart rate?

The most common formula is 220 − age (Fox, 1971). A more accurate formula for most adults is 208 − 0.7 × age (Tanaka, 2001). For women specifically, 206 − 0.88 × age (Gulati, 2010) may be more accurate. A newer formula is 211 − 0.64 × age (Nes, 2013). Lab-based stress testing is the gold standard.

What heart rate burns the most fat?

Zone 2 (60–70% of max HR) burns the highest percentage of calories from fat. However, higher-intensity zones burn more total calories per minute. For optimal fat loss, combine Zone 2 endurance sessions (30–60 min) with Zone 4 interval training, alongside a calorie deficit from your diet.

What is a dangerous heart rate during exercise?

Exceeding your estimated max heart rate (220 − age) for extended periods can be dangerous and may indicate overexertion. Warning signs include chest pain, dizziness, shortness of breath, or irregular heartbeat. If your resting heart rate is consistently above 100 bpm (tachycardia), consult a doctor. Always build intensity gradually.

How do I find my resting heart rate?

Measure your pulse first thing in the morning before getting out of bed. Place two fingers on the inside of your wrist (thumb side) and count beats for 60 seconds, or count for 15 seconds and multiply by 4. Average over 3–5 days for accuracy. Normal adult resting HR is 60–100 bpm; athletes may be 40–60 bpm.

Is the Karvonen method more accurate than simple percentage of max HR?

Yes. The Karvonen method uses heart rate reserve (max HR minus resting HR), which accounts for your individual fitness level. Two people of the same age with different resting heart rates will get different — and more personalized — training zones. Simple percentage-of-max ignores resting HR entirely.

What is a good resting heart rate?

For most adults, 60–100 bpm is normal. A lower resting heart rate generally indicates better cardiovascular fitness. Well-trained athletes may have a resting HR of 40–60 bpm. A resting HR consistently above 100 bpm (tachycardia) or below 50 bpm with symptoms warrants medical evaluation.

How long should I train in Zone 2?

Most endurance coaches recommend spending 80% of total weekly training volume in Zone 2. Individual Zone 2 sessions typically last 30–90 minutes for general fitness, or 60–180 minutes for endurance athletes. Zone 2 builds mitochondrial density, capillary growth, and fat oxidation capacity.

Should I use a chest strap or wrist heart rate monitor?

Chest straps (like Polar H10) measure electrical signals and are the most accurate for real-time zone training. Wrist optical sensors in smartwatches are convenient but can lag during high-intensity work and may be less accurate during activities with wrist movement. For serious zone-based training, use a chest strap.

What is the talk test for exercise intensity?

The talk test is a simple way to gauge intensity without a heart rate monitor. Zone 1–2: you can hold a normal conversation. Zone 3: you can speak in short sentences. Zone 4: you can only say a few words at a time. Zone 5: you cannot talk at all. It correlates well with heart rate zones in research studies.

Target Heart Rate Calculator

Find your 5 training zones, Zone 2 fat-burning range, and max heart rate using the Karvonen method and 4 validated formulas.

Your target heart rate for moderate exercise is 50–70% of your max HR (roughly 220 minus your age). For vigorous exercise, aim for 70–85%. Zone 2 (60–70%) is the optimal fat-burning zone. Enter your age and resting heart rate below to calculate all 5 personalized training zones using the Karvonen formula.

Based on Karvonen method with formulas from Tanaka (2001), Fox (1971), Gulati (2010), and Nes (2013). Data sourced from American Heart Association guidelines.

Calculate Your Target Heart Rate Zones

Age

years

Resting Heart Rate (measure in the morning)

bpm

Max Heart Rate Formula

Quick Answer: Target Heart Rate at a Glance

•Max Heart Rate: 220 − your age (Fox) or 208 − 0.7 × age (Tanaka, more accurate).
•Moderate exercise: 50–70% of max HR (AHA guideline).
•Vigorous exercise: 70–85% of max HR.
•Zone 2 (fat burning): 60–70% of max HR — build endurance at conversational pace.
•Karvonen formula: THR = (Max HR − Resting HR) × intensity% + Resting HR.

How to calculate your target heart rate

Your target heart rate (THR) is the ideal heart rate range for a specific exercise intensity. The simplest method multiplies your max heart rate by a percentage. The Karvonen method is more accurate because it factors in your resting heart rate, which reflects your individual fitness level. Two people of the same age but different resting heart rates will get different — and more personalized — training zones.

Karvonen Formula

THR = (Max HR − Resting HR) × intensity% + Resting HR

Target heart rate chart by age (AHA)

This table shows target heart rate zones based on the American Heart Association guidelines using the 220 − age formula. Target HR during moderate-intensity activity is 50–70% of max. During vigorous activity, it is 70–85%.

Target Heart Rate by Age (Source: American Heart Association)
Age	Max HR (bpm)	Moderate (50–70%)	Vigorous (70–85%)
20	200	100–140	140–170
25	195	98–137	137–166
30	190	95–133	133–162
35	185	93–130	130–157
40	180	90–126	126–153
45	175	88–123	123–149
50	170	85–119	119–145
55	165	83–116	116–140
60	160	80–112	112–136
65	155	78–109	109–132
70	150	75–105	105–128

Zone 2 heart rate by age

Zone 2 (60–70% of max HR) is the most discussed training zone for fat loss and endurance building. It is the intensity where your body primarily uses fat as fuel, and you can maintain a conversational pace. Most endurance coaches recommend spending 80% of training time in Zone 2. The table below shows Zone 2 ranges by age using both the simple formula and the Karvonen method (assuming resting HR of 65 bpm).

Zone 2 Heart Rate by Age
Age	Max HR	Zone 2 (simple %)	Zone 2 (Karvonen, RHR 65)
20	200	120–140	146–160
25	195	117–137	143–156
30	190	114–133	140–153
35	185	111–130	137–149
40	180	108–126	134–146
45	175	105–123	131–142
50	170	102–119	128–139
55	165	99–116	125–135
60	160	96–112	122–132
65	155	93–109	119–128
70	150	90–105	116–125

Max heart rate formulas compared

Multiple formulas exist to estimate max heart rate. No formula is perfect — individual variation is ±10–15 bpm. Lab-based stress testing is the gold standard. The table below compares the four most commonly used formulas.

Max Heart Rate Formula Comparison
Formula	Equation	Age 30	Age 40	Age 50	Best For
Fox (1971)	220 − age	190	180	170	Quick estimate
Tanaka (2001)	208 − 0.7 × age	187	180	173	Most adults (recommended)
Gulati (2010)	206 − 0.88 × age	180	171	162	Women
Nes (2013)	211 − 0.64 × age	192	185	179	Newer, healthy adults

The 5 heart rate training zones explained

Each training zone produces different physiological adaptations. Understanding what each zone targets helps you design more effective workouts.

Heart Rate Training Zones
Zone	% Max HR	Training Effect	Talk Test	Example Activity
1 — Recovery	50–60%	Active recovery, blood flow	Easy conversation	Walking, light yoga
2 — Fat Burn	60–70%	Fat oxidation, endurance base	Conversational pace	Brisk walk, easy jog
3 — Aerobic	70–80%	Cardio fitness, efficiency	Short sentences only	Tempo run, cycling
4 — Anaerobic	80–90%	Speed, lactate threshold	Few words at a time	Intervals, hill sprints
5 — VO2 Max	90–100%	Maximum output, VO2 max	Cannot talk	All-out sprints (1–3 min)

Zone 2 training: the fat-burning zone explained

Zone 2 (60–70% of max HR) has become one of the most discussed concepts in fitness. At this intensity, your body derives the highest percentage of energy from fat oxidation. You can maintain conversational pace and sustain the effort for extended periods — making it ideal for building aerobic endurance without accumulated fatigue. Research shows Zone 2 training improves mitochondrial density, capillary growth, and the body's ability to use fat as fuel. Most endurance coaches recommend spending 80% of weekly training volume in Zone 2, with the remaining 20% in higher-intensity zones (polarized training model). For fat loss specifically, combining Zone 2 endurance sessions (30–60 minutes) with Zone 4 interval work and a calorie deficit produces the best results.

Resting heart rate: what is normal?

A normal resting heart rate for adults ranges from 60–100 bpm, though recent research suggests 50–90 bpm is a more accurate range. A lower resting HR generally indicates better cardiovascular fitness — the heart is more efficient at pumping blood. Well-trained endurance athletes can have resting heart rates as low as 40 bpm. Factors that affect resting HR include fitness level, stress, caffeine, medication, temperature, and body position. A resting HR consistently above 100 bpm (tachycardia) or below 50 bpm with symptoms should be evaluated by a healthcare provider.

Resting Heart Rate Reference
Category	Resting HR (bpm)	Indication
Elite athlete	40–50	Excellent cardiovascular efficiency
Very fit	50–60	Strong aerobic conditioning
Average	60–75	Normal, healthy range
Below average	75–90	May benefit from more cardio
Elevated	90–100+	Consider consulting a doctor

Nutrition for zone-based training

Different training zones have different fuel demands. Zone 1–2 sessions primarily burn fat and don't require special fueling for sessions under 90 minutes. Zone 3–4 sessions rely more heavily on glycogen — ensure adequate carbohydrate intake before and after. Zone 5 sessions are short but intense; a small carb-rich snack 30–60 minutes beforehand can improve performance. Post-workout protein (20–40 g) supports muscle recovery regardless of which zone you trained in.

Fueling by Training Zone
Zone	Primary Fuel	Pre-Workout	Post-Workout
1–2	Fat	Optional (can train fasted)	Protein, light meal
3	Fat + Glycogen	Moderate carbs 1–2h before	Protein + carbs
4–5	Glycogen	Carb-rich snack 30–60 min before	Protein + carbs within 30 min

Key Takeaways

Target heart rate for moderate exercise is 50–70% of max HR (AHA guideline).
Max HR formula: 220 − age (simple) or 208 − 0.7 × age (Tanaka, more accurate).
Zone 2 (60–70%) is the optimal fat-burning and endurance-building zone.
The Karvonen method personalizes zones using resting heart rate.
Spend 80% of training in Zone 2, 20% in higher zones for optimal results.
A lower resting heart rate generally indicates better cardiovascular fitness.

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Match Your Training with the Right Nutrition

Zone-based training demands the right fuel. Use our macro calculator to dial in your nutrition, then let our AI create a personalized meal plan matched to your training intensity.

Scientific references

Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001;37(1):153-156.
Fox SM, Naughton JP, Haskell WL. Physical activity and the prevention of coronary heart disease. Ann Clin Res. 1971;3(6):404-432.
Gulati M, et al. Heart rate response to exercise stress testing in asymptomatic women. Circulation. 2010;122(2):130-137.
Nes BM, Janszky I, Wisløff U, Støylen A, Karlsen T. Age-predicted maximal heart rate in healthy subjects. Scand J Med Sci Sports. 2013;23(6):697-704.
Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate. Ann Med Exp Biol Fenn. 1957;35:307-315.
American Heart Association. Target Heart Rates Chart. heart.org. Updated 2024.