Heart Rate Zone Calculator
Free heart rate zone calculator for Zones 1-5. Enter your age, resting heart rate, and formula choice to get training zones for walking, running, cycling, and challenge workouts.
Heart Rate Zone Calculator
Your numbers
Enter a tested max if you have one. Otherwise the calculator uses 208 - (0.7 x age).
Formula
Training goal
Zones 1-5
Estimates only. Medications, heat, caffeine, stress, sleep, and fatigue can all change heart rate. Use perceived effort with the bpm range.
How this heart rate zone calculator works
The calculator starts with your maximum heart rate. If you know your tested max, use it. If not, the calculator estimates it with 208 - (0.7 x age), then builds five zones from 50% to 100% intensity. Each zone gets a bpm range, a plain-English effort cue, and a practical use case.
Resting heart rate matters too. A trained runner with a resting heart rate of 48 and a new exerciser with a resting heart rate of 78 should not get identical targets just because they are the same age. That is why the default mode uses heart rate reserve.
Karvonen vs max heart rate percentage
The simple method multiplies max heart rate by each zone percentage. It is easy to read and matches many wall charts. The Karvonen method uses this formula: ((max HR - resting HR) x intensity) + resting HR. It usually produces higher working targets for fit users because it accounts for the gap between resting and max heart rate.
Pick "Compare both" if you are setting up a watch or bike computer and want to see how the ranges differ. Once you choose a method, stick with it for a training block so your easy days, tempo days, and interval days stay consistent.
How to use zones during a 75-day challenge
For most daily challenge workouts, Zone 2 is the sweet spot. You should be able to speak in short sentences, finish the workout without feeling crushed, and come back tomorrow. That is useful when you are also following a diet, drinking water, reading, and logging progress photos.
Use Zone 1 for recovery walks, Zone 2 for outdoor cardio, Zone 3 for steady tempo work, and Zones 4 to 5 for short intervals. If you are planning daily workouts inside Reset75, keep hard interval days limited so the whole challenge stays repeatable.
Why heart rate zones are still estimates
Age formulas are useful, but they are not lab tests. Your true max heart rate can sit well above or below the estimate, and wrist sensors can drift during cold weather, gripping, sweat, or fast intervals. If your breathing and perceived effort disagree with the number, trust your body and adjust the target.
For more planning context, pair this with the outdoor workout generator, two-a-day workout planner, and 75-day challenge calculator.
Frequently Asked Questions
Common questions about heart rate zone calculator
What is a heart rate zone calculator?
A heart rate zone calculator turns your age, resting heart rate, and max heart rate into training ranges. Each zone gives you a bpm target for easy recovery, aerobic base work, tempo sessions, threshold work, and short hard intervals.
How do I calculate my heart rate zones?
Estimate your max heart rate, then apply a percentage range to that number. The Karvonen method adds resting heart rate to the formula, so it usually gives more personal zones than a simple max-heart-rate percentage chart.
What is the Karvonen formula?
The Karvonen formula uses heart rate reserve: ((max HR - resting HR) x intensity) + resting HR. It accounts for a low or high resting heart rate, which makes it useful for people who train regularly.
Is Zone 2 the best zone for fat loss?
Zone 2 is useful because it is easy enough to repeat often and hard enough to build aerobic capacity. Fat loss still comes from your weekly calorie balance, so pair Zone 2 cardio with a realistic intake target from the calorie deficit calculator.
What heart rate zone should I use for a 75-day challenge workout?
Most outdoor challenge workouts fit Zone 2 or low Zone 3. That keeps the session repeatable while you handle daily training, water, diet, reading, and photos. Save Zone 4 and Zone 5 for planned interval days, not every workout.
Is 220 minus age accurate for max heart rate?
It is a rough estimate, not a measurement. This calculator uses the Tanaka estimate by default and lets you enter a tested max heart rate if you know it. A lab or field test will be more accurate than any age formula.
Why are my watch zones different from this calculator?
Watches may use a different max heart rate formula, lactate threshold zones, or old resting heart rate data. Check the formula inside your watch app, then update max HR and resting HR so the ranges match your current fitness.
When should I ask a doctor about heart rate targets?
Ask a clinician before using heart rate targets if you have chest pain, dizziness, heart disease, high blood pressure, pregnancy concerns, or medications that affect heart rate. The numbers here are fitness estimates, not medical advice.