Heart Rate Calculator: How to Find Your Target Heart Rate Zones for Maximum Fitness Results

Your heart rate is the most direct, real-time feedback you can get during exercise. It tells you exactly how hard your heart is working and whether you are in the right zone for your fitness goals. Whether you want to burn fat, build endurance, or improve cardiovascular health, training in the correct heart rate zone makes the difference between effective workouts and wasted effort.

Use the Heart Rate Calculator on TodayCalculator to quickly find your target heart rate zones based on your age and resting heart rate.

The Five Heart Rate Zones

Zone	% of Max HR	Intensity	Benefits	Typical Activity
Zone 1	50-60%	Very light	Recovery, warm-up, fat burning	Walking, light cycling
Zone 2	60-70%	Light	Endurance, aerobic base, fat adaptation	Jogging, steady cycling
Zone 3	70-80%	Moderate	Cardiovascular fitness, lactate threshold	Running, swimming laps
Zone 4	80-90%	Hard	Speed, power, VO2 max	Interval training, HIIT
Zone 5	90-100%	Maximum	Sprint performance, neuromuscular power	All-out sprints, max effort

How to Calculate Your Max Heart Rate

The simplest formula for estimating your maximum heart rate is the Tanaka formula: 208 – (0.7 × age). This is more accurate than the older 220-age formula, especially for adults over 40. For example, a 35-year-old has an estimated max HR of 208 – (0.7 × 35) = 183 bpm.

For a more precise calculation that accounts for your fitness level, use the Heart Rate Calculator which factors in your resting heart rate as well.

Training by Goal: Which Zone to Use

Fat loss: Spend 70% of workout time in Zone 2. Your body burns a higher percentage of fat for fuel at this intensity.
Endurance: Zone 2-3. Build aerobic capacity by spending 45-60 minutes in these zones, 3-4 times per week.
Speed and performance: Zone 4-5 intervals. Alternate 2 minutes in Zone 4 with 2 minutes of recovery for 4-6 rounds.
Heart health: Zone 1-3. The American Heart Association recommends 150 minutes per week of moderate activity (Zone 2-3).

Monitoring Your Heart Rate During Workouts

A chest strap heart rate monitor is the most accurate for zone training. Wrist-based optical sensors (on smartwatches) work well for steady-state but can lag during intervals. Check your heart rate 2-3 times per workout session to confirm you’re in the target zone, especially during the transition between zones.

Calculate your personal zones at the Heart Rate Calculator and train smarter, not harder.