Heart Rate Calculator
What Is My Target Heart Rate?
Find your maximum heart rate and 5 personalised training zones -- fat burning, cardio, anaerobic, and peak. WhatsApp share card and free PDF report included. Based on American Heart Association guidelines.
What Is Target Heart Rate?
Understanding your heart rate zones transforms exercise from guesswork into precision training. Without zone awareness, most people exercise either too easy (not challenging enough to improve fitness) or too hard (risking overtraining and injury). Heart rate zone training allows you to target exactly the right intensity for your specific goal -- whether that is losing weight, building cardiovascular endurance, or improving athletic performance.
Heart rate training zones also help you stay safe. This is particularly important for beginners, those returning to exercise after a break, and anyone with cardiovascular risk factors. Always consult your doctor before starting a new exercise programme, especially if you have high blood pressure, diabetes risk, or are over 40 and currently inactive.
How to Calculate Maximum Heart Rate
Maximum heart rate (MHR) is the highest number of beats per minute your heart can achieve during maximum effort. It decreases with age -- roughly 1 bpm per year. Three validated formulas are available, each with different levels of accuracy:
- AHA Formula (220 - age): The most widely known formula. Simple and broadly accurate, but overestimates MHR for younger adults and underestimates for older adults. Standard clinical reference.
- Tanaka Formula (208 - 0.7 x age): Derived from a meta-analysis of 351 studies involving 18,712 subjects. More accurate for adults over 40. Recommended for middle-aged and older adults.
- Gellish Formula (206.9 - 0.67 x age): Considered the most accurate across all age groups in research. Particularly useful for those with unusually high or low MHR relative to age predictions.
Important: all MHR formulas are population-based estimates with standard deviations of approximately 10-12 bpm. Your actual MHR may be significantly higher or lower than the calculation. The only way to know your true MHR is through a medically supervised maximal exercise test (VO2max test). Use our VO2 Max Calculator to estimate your cardiorespiratory fitness level.
The 5 Heart Rate Training Zones Explained
| Zone | % of MHR | Perceived Effort | Primary Benefit | Time Limit |
|---|---|---|---|---|
| Zone 1 -- Warm Up | 50-60% | Very easy, can sing | Recovery, general health, active rest | Unlimited |
| Zone 2 -- Fat Burn | 60-70% | Easy, full conversation | Fat oxidation, aerobic base, endurance | 30-90 min+ |
| Zone 3 -- Cardio | 70-80% | Moderate, short sentences | Cardiovascular fitness, aerobic capacity | 20-60 min |
| Zone 4 -- Anaerobic | 80-90% | Hard, few words only | Speed, power, lactate threshold | 5-20 min |
| Zone 5 -- Maximum | 90-100% | Maximum, cannot speak | Peak performance, VO2max improvement | 30 sec-3 min |
Zone 1 -- Recovery and Warm-Up (50-60% MHR)
Zone 1 is very light activity -- easy walking, gentle yoga, or cool-down activity. At this intensity, the cardiovascular system is barely challenged and fat is the primary fuel source. Zone 1 is essential for active recovery between harder training sessions, as it promotes blood flow to muscles without adding additional stress. Many elite athletes spend the majority of their training time in Zones 1 and 2.
Zone 2 -- Fat Burning and Aerobic Base (60-70% MHR)
Zone 2 is the most important zone for long-term health and weight management. At this intensity, the body uses fat as its primary fuel source and builds the mitochondrial density that underlies all endurance capacity. Consistent Zone 2 training builds the "aerobic base" that makes all other zones feel easier. For weight loss, Zone 2 is effective -- but higher zones burn more total calories per minute. Combine with our Weight Loss Calculator for a complete fat loss plan.
Zone 3 -- Cardio Fitness (70-80% MHR)
Zone 3 is moderate-to-hard intensity -- jogging, cycling at a steady pace, or swimming laps. This zone improves cardiovascular fitness and is where most "cardio" training occurs. The body uses a mix of fat and carbohydrates as fuel. Zone 3 training strengthens the heart muscle, improves stroke volume, and lowers resting heart rate over time. Check your calories burned during Zone 3 exercise to understand your energy expenditure.
Zone 4 -- Anaerobic Threshold (80-90% MHR)
Zone 4 is hard intensity where lactic acid begins to accumulate faster than the body can clear it -- the "anaerobic threshold." Training at this zone raises the threshold, allowing you to sustain higher speeds before fatigue. Zone 4 is used in HIIT (high-intensity interval training), tempo runs, and competitive sports training. Stay in this zone for only 5-20 minutes per session as it is demanding on the cardiovascular and musculoskeletal systems.
Zone 5 -- Maximum Effort (90-100% MHR)
Zone 5 is all-out maximum effort -- sprints, maximum intervals, and competitive race pace. Carbohydrates are almost the exclusive fuel source. This zone is only sustainable for 30 seconds to 3 minutes at a time. It stimulates powerful adaptations in VO2max and fast-twitch muscle fibres. Zone 5 work is only appropriate for those with a solid aerobic base and should not be performed by beginners or those with cardiovascular risk factors without medical clearance.
What Heart Rate Burns the Most Fat?
The "fat burning zone" is often misunderstood. While it is true that moderate-intensity exercise burns a higher proportion of calories from fat, total calorie expenditure is what matters most for weight loss. A 30-minute Zone 3 session burns more total calories -- and therefore more total fat -- than a 30-minute Zone 2 session. For optimal fat loss, combine both zones. Use our Calorie Calculator to understand your total daily energy needs alongside your exercise programme.
Resting Heart Rate and Cardiovascular Fitness
Your resting heart rate (RHR) is one of the simplest and most powerful indicators of cardiovascular health. A lower resting heart rate generally indicates better heart efficiency -- the heart pumps more blood per beat and therefore requires fewer beats to meet the body's baseline needs. Track changes in your RHR over time to monitor your fitness progress:
- Athlete (28-55 bpm): Exceptional cardiovascular fitness. Common in elite endurance athletes like marathon runners and cyclists
- Excellent (56-65 bpm): Very good cardiovascular fitness
- Good (66-75 bpm): Above average cardiovascular health
- Average (76-85 bpm): Normal for most adults
- Below average (86-95 bpm): Benefit from more cardiorespiratory exercise
- Poor (96+ bpm): Consult a doctor -- consistently elevated RHR can indicate cardiovascular issues
Regular cardiovascular exercise typically lowers resting heart rate by 5-25 bpm over several months. This reduction is a direct sign that the heart has become more efficient. Monitor your blood pressure alongside heart rate with our Blood Pressure Checker -- high blood pressure and elevated resting heart rate often co-occur and both respond well to regular aerobic exercise.
The Karvonen Formula -- More Accurate Zone Calculation
The Karvonen formula uses Heart Rate Reserve (HRR = MHR - RHR) to calculate personalised training zones that account for individual fitness levels. Two people of the same age with different resting heart rates will have different optimal training zones even if their MHR is the same.
Karvonen formula: Target HR = (HRR x intensity%) + RHR
For example, a 35-year-old with MHR of 185 and RHR of 60 (HRR = 125) training at 70%: Target HR = (125 x 0.70) + 60 = 87.5 + 60 = 147.5 bpm. Without Karvonen, the same person's 70% zone would simply be 185 x 0.70 = 129.5 bpm. The Karvonen method gives a higher, more challenging -- and more accurate -- target for a fit individual with a low resting heart rate.
How to Improve Cardiovascular Health Through Exercise
- Start with Zone 2 base building: If you are new to exercise, spend the first 4-8 weeks training primarily in Zone 2. This builds the aerobic base that makes all subsequent training more effective and sustainable
- Gradually add Zone 3-4 sessions: Once you have an aerobic base, add 1-2 higher-intensity sessions per week. HIIT (high-intensity interval training) has been shown to improve cardiovascular fitness more rapidly than steady-state cardio in time-constrained individuals
- Aim for 150 minutes of moderate activity per week: The WHO recommends at least 150-300 minutes of moderate-intensity or 75-150 minutes of vigorous-intensity aerobic activity per week for adults
- Track your resting heart rate: Check your RHR every morning. A decrease of 5+ bpm over 8-12 weeks of regular training confirms your cardiovascular fitness is improving
- Stay hydrated during exercise: Dehydration increases heart rate for any given exercise intensity, making every zone feel harder. Use our Water Intake Calculator to find your personalised hydration target
- Prioritise sleep for recovery: Heart rate adaptations to exercise occur during rest and sleep. Use our Sleep Calculator to optimise your recovery sleep cycles
- Address diabetes risk: Type 2 diabetes significantly impairs cardiovascular health. Regular zone-based exercise is one of the most powerful interventions for reducing diabetes risk. Check yours with our Diabetes Risk Calculator
