Target Heart Rate Zones Calculator
Turn age and resting pulse into simple training zones
Heart rate zones, safety and training FAQ
How do you estimate maximum heart rate in this tool?
This page uses a Tanaka-style equation that predicts maximum heart rate as roughly 208 − 0.7 × age in healthy adults. Large reviews suggest that formulas in this family can track measured HRmax better than the older “220 − age” rule in many groups, but every formula still has a margin of error of about a dozen beats per minute.
What is the difference between %HRmax and Karvonen zones?
%HRmax zones use a straight percentage of estimated maximum heart rate. Karvonen, or heart rate reserve (HRR), subtracts resting heart rate first, then applies the percentage and adds resting back in. For some people, especially those with very low or high resting pulses, HRR zones may feel closer to how hard the work actually feels.
Which heart rate zone is best for fat loss or endurance?
There is no single magic zone. Many plans lean on Zone 2 (about 60–70% of HRmax) for long, easy sessions, then add shorter blocks in Zones 3–4 to build threshold and speed. Calorie burn depends most on time, total work and consistency, not on hitting a precise bpm number every minute.
How do perceived effort (RPE) and pace fit in?
Many runners and riders use RPE scales and pace alongside heart rate. Zone 1–2 often feel like “easy conversation pace”; Zone 3 like “steady but talking in short phrases”; Zone 4 like “hard, short sentences only”; and Zone 5 like “very hard, a few words at a time”. Using more than one signal makes you less dependent on any single gadget or equation.
My watch zones don’t match these. Who is right?
Different brands use different formulas, rounding rules and resting heart rate assumptions. Some take values from a paired chest strap or from recent workouts. Think of this page as a transparent baseline you can compare with your device. If your watch is based on a lab test or long history of runs, it may be closer to your true zones than any generic equation.
Is it safe to train near maximum heart rate?
Brief, well-planned high-intensity work can be helpful for many people who are already cleared for vigorous exercise. But long stretches at or above 90% of HRmax are not the starting point for beginners or people with heart or lung disease. If you are unsure, have symptoms (pain, pressure, unusual breathlessness, faintness) or take heart medicines, you need medical guidance first.
What if my heart rate never matches these zones?
Equations are averages. Medications such as beta blockers, pacemakers, fitness level, genetics, heat, sleep, hydration and measurement error can all shift your numbers. If your heart rate at a given effort is consistently far outside the predicted ranges, especially with symptoms, bring that pattern to a clinician rather than forcing yourself to “hit the chart”.
How to use this target heart rate zones calculator
The goal of this page is to turn abstract heart rate math into zones you can use during runs, rides, classes or brisk walks. Instead of trying to remember percent ranges in your head, you get a clear max heart rate estimate and five labelled zones with pace and effort cues.
1. Enter age and resting heart rate
Start with your current age. If you know it, add a resting heart rate taken when you are calm, relaxed and not on caffeine—many people use the lowest reading from their watch overnight or a morning pulse counted for 30–60 seconds. If you leave resting HR blank, you will still get %HRmax zones; filling it in unlocks the Karvonen heart rate reserve column.
2. Pick a primary training focus
The “Primary goal” dropdown is optional. Choose Easy endurance if you mostly want long, sustainable work; Tempo / threshold if you care about race-pace sessions; or Intervals if you often do short, hard efforts. The calculator uses that choice to highlight the zone or zones that usually match that focus so your eyes know where to land first.
3. Read HRmax and the five zones
Hit Calculate heart rate zones to see:
- An estimated maximum heart rate from your age.
- A quick line for moderate (≈50–70%) and vigorous (≈70–85%) intensity, matching common health guidelines.
- A table of five zones with %HRmax, bpm from HRmax, and, if you entered resting HR, bpm from Karvonen HRR plus effort cues.
You can use the Copy summary button to paste the key numbers into a training plan, coaching notes or your phone’s notes app for later.
4. Combine zones with RPE and pace
Heart rate reacts to heat, stress, caffeine and fatigue. That is why coaches often ask you to combine zones with how hard it feels (RPE) and, where relevant, pace or power. If your watch shows Zone 2 but your breathing feels like Zone 4, trust your body and back off, then review sleep, illness and stress rather than pushing blindly.
If you are new to structured training, consider starting with more time in Zones 1–2, sprinkled with short, intentional blocks in higher zones only after you feel confident with the basics. Anyone with diagnosed heart disease, significant risk factors, or concerning symptoms should work directly with a healthcare team before using aggressive zone work.
How the max heart rate and Karvonen math works
The math on this page is deliberately simple and widely used in exercise science. The main moving parts are an age-based formula for HRmax, standard percent ranges for zones, and the classic Karvonen heart rate reserve method.
1. Estimating maximum heart rate from age
Instead of the traditional “220 − age” rule, this calculator uses:
HRmax ≈ 208 − 0.7 × age
This style of equation has been shown in large samples to track lab-measured HRmax a bit better on average, especially in older adults, although individual error can still be 7–12 beats per minute or more.
2. Building five %HRmax zones
Once HRmax is estimated, the tool builds five zones using percentage bands similar to those described by major health organisations and endurance coaches:
- Zone 1: 50–60% of HRmax (very easy / recovery).
- Zone 2: 60–70% of HRmax (easy aerobic endurance).
- Zone 3: 70–80% of HRmax (steady, “comfortably hard”).
- Zone 4: 80–90% of HRmax (hard, near threshold).
- Zone 5: 90–100% of HRmax (very hard, short efforts).
Each band is applied directly to HRmax to get a lower and upper bpm value for the %HRmax column.
3. Adding Karvonen heart rate reserve
When you share a resting pulse, the calculator also shows Karvonen-based targets using:
HRR = HRmax − HRrest
Target bpm = HRrest + % × HRR
So, for Zone 2 (60–70%), the Karvonen column becomes:
Low = HRrest + 0.60 × HRR
High = HRrest + 0.70 × HRR
This anchors training intensity to both your maximum and resting heart rates, which can be useful for people whose resting pulses sit far from population averages.
4. Rounding and practical use
All values are rounded to whole beats per minute to match most watch and treadmill displays. The important thing is not exact decimals but rough zones that feel right once you combine heart rate with breathing, pace, power and symptoms. If something feels off, your sensations and your clinician’s advice always outrank the calculator.
References and further reading on target heart rate zones
These resources explain where the equations and heart rate ranges in this tool come from:
- Tanaka H et al. — Age-predicted maximal heart rate revisited — meta-analysis proposing HRmax ≈ 208 − 0.7 × age and discussing accuracy vs the older 220 − age rule.
- Ignaszewski M — The science of exercise prescription: Martti Karvonen and his contributions — overview of the Karvonen heart rate reserve method and how it links training zones to resting and maximum heart rate.
- American Heart Association — Target heart rates chart — practical discussion of moderate (50–70%) and vigorous (70–85%) intensity ranges and how to monitor exertion safely.
Use these as background reading, then combine the calculator’s zones with any specific exercise testing, device data and medical advice you already have.