Target Heart Rate Calculator
Find the beats per minute to aim for in each training zone, from your age or a tested maximum. Add your resting heart rate and the zones are personalised to your own reserve rather than to a population average.
Max heart rate estimation formula
Activity intensity scale
Every zone is derived from these two figures, so an error in either moves the whole table.
| Formula | Equation | Your max |
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All three predict a group average, not you. A tested maximum from a supervised stress test beats every one of them.
Three numbers, and only one is yours
Everything on this page is built from three figures. Your maximum heart rate is the ceiling your heart can reach under all-out effort. Your resting heart rate is where it sits when you are awake, calm and not doing anything. The gap between them is your heart rate reserve, and that gap is the room you actually have to work with.
The awkward part is that only the resting figure is genuinely measured. Unless you have done a supervised stress test, your maximum is a guess produced by an equation fitted to a large group of people, and individuals scatter widely around it. Two people of the same age can differ by twenty beats or more, which is enough to shift every zone in the table.
That is worth knowing before you treat any of these numbers as a rule. They are a starting range, not a prescription, and the sensible way to use them is as a rough map that you correct against how the effort actually feels.
Why resting rate changes the answer
Leave the resting box blank and the calculator falls back to straight percentages of your maximum. Fill it in and it switches to the Karvonen method, which works from your reserve instead. The two produce noticeably different targets, and the second is the better one.
target = maximum × percentage
With one, the Karvonen method
reserve = maximum − resting
target = resting + (reserve × percentage)
Worked through at 70% for a 34-year-old resting at 62
maximum = 220 − 34 = 186 bpm
reserve = 186 − 62 = 124 bpm
target = 62 + (0.70 × 124) = 149 bpm
against 0.70 × 186 = 130 bpm the other way — a gap of 19 beats
Nineteen beats is not a rounding difference; it is the difference between an easy jog and real work. The plain-percentage version ignores where your heart actually starts from, so it under-prescribes for almost everybody and does so most severely for the fittest people, whose resting rates are lowest.
Measure your resting rate properly if you are going to use it. First thing in the morning, before getting up, before caffeine. Count for a full minute rather than fifteen seconds and multiplying, and take an average across a few days — a single reading catches whatever your night happened to be like.
Picking a formula for your maximum
Three equations sit behind the settings, and they disagree with each other more as you move away from middle age.
Haskell and Fox, 220 minus age. Published in 1971 and the one nearly everybody has heard of. Its authors never intended it as a research finding; it was an observation drawn from existing data. It is the default here because it is the reference point everyone else is compared against, not because it is the best.
Tanaka, Monahan and Seals, 208 minus 0.7 times age. A 2001 meta-analysis built on a much larger pool of studies. Its gentler slope means it reads lower than 220-minus-age for the young and higher for the old, and the crossover sits around forty. For most adults over forty it is the better-supported choice.
Nes and colleagues, 211 minus 0.64 times age. From a 2013 Norwegian study of more than three thousand healthy adults, with maximums actually measured rather than pooled from the literature. A reasonable modern alternative.
Try all three on your own age and look at the spread. At twenty they land within a few beats of each other; at seventy they separate by close to ten. That spread is the honest error bar on the whole exercise, and no amount of choosing between them removes it.
What each zone is actually for
The five bands are not a ladder where higher is better. Each does a different job, and a sensible week uses several.
Very light, 50 to 60%. Warm-ups, cool-downs and recovery days. It should feel like you could keep going indefinitely, because you could.
Light, 60 to 70%. The base of most endurance training and where a large share of a serious plan actually sits. Conversation is comfortable. This band is often labelled fat-burning, which is true in the narrow sense that a higher proportion of the energy comes from fat — but harder work burns more total energy in the same time, so the label misleads more than it helps.
Moderate, 70 to 80%. Aerobic development. Talking becomes short sentences rather than paragraphs. Sustained effort here is what raises the ceiling over months.
Hard, 80 to 90%. Around and above the point where lactate starts accumulating faster than you clear it. Effective in intervals, expensive in recovery.
Maximum, 90 to 100%. Short repeats only, and never the bulk of a week. Most improvement comes from the easier bands; this one is a seasoning.
The common mistake is spending every session in the middle — too hard to recover from, too easy to drive real adaptation. Easy days genuinely easy and hard days genuinely hard tends to beat a week of moderate everything.
When the number on your wrist is the wrong tool
The other two settings drop heart rate percentages and use a rating you give yourself instead. The Borg scale runs 6 to 20, chosen so that multiplying by ten roughly lands on a heart rate for a healthy adult. The CR10 version runs 0 to 10 and is easier to hold in your head.
Perceived exertion is not a lesser substitute. It reads the whole picture — breathing, legs, heat, how the day feels — while heart rate reads one channel and lags behind changes in effort by up to a couple of minutes. On a short hill or in an interval, your rating is accurate before your monitor catches up.
It also keeps working where heart rate does not: on beta blockers, which flatten the whole range; in heat, where the rate climbs without the work getting harder; when you are dehydrated, ill or short on sleep. The table here shows what each rating tends to correspond to in beats, so you can learn how the two line up on your own body and then trust the rating when the number looks wrong.
Reasons your heart rate lies today
A target zone assumes today is a normal day. Several ordinary things make the same effort produce a different number, and reading them as fitness changes will send you the wrong way.
Heat and humidity push the rate up as blood is diverted to the skin, sometimes by ten beats or more at identical pace. Dehydration does the same by thinning blood volume. A poor night, a coming cold, alcohol the evening before, caffeine an hour before, and altitude all raise it. Cardiac drift raises it steadily through any long session even at constant effort. Chest straps and wrist optical sensors also disagree, especially during intervals and in the cold.
None of that means abandon the zones. It means that when your rate is fifteen beats high at an easy pace, the most likely explanation is one of the above and the right response is usually to go easier, not to push until the number matches.
When to stop and ask a doctor
These zones assume a healthy heart and a person cleared for vigorous exercise. That is not everyone, and the calculator cannot tell the difference.
Speak to a doctor before using the upper bands if you have any diagnosed heart condition, high blood pressure, diabetes, or a family history of early cardiac problems; if you take beta blockers or other rate-controlling medication, in which case these numbers do not apply at all; if you are pregnant; or if you are returning to exercise after a long gap or a significant illness.
Stop and seek help regardless of what your monitor says if you get chest pain, pressure or tightness, sudden shortness of breath out of proportion to the effort, dizziness or faintness, an irregular or racing heartbeat that does not settle with rest, or pain spreading into the arm, neck or jaw. No target is worth working through any of those.
Frequently asked questions
How do I calculate my target heart rate?
Start with your maximum — 220 minus your age is the familiar version. Without a resting rate, multiply that by the percentage you want. With one, use the Karvonen method: subtract resting from maximum to get your reserve, multiply the reserve by the percentage, then add resting back. For a 34-year-old resting at 62, seventy percent works out at 149 bpm.
Is 220 minus age accurate?
Only loosely. It came from an observation of existing data in 1971 rather than from a study designed to establish it, and individuals scatter widely around any such average — two people of the same age can differ by twenty beats. The Tanaka equation has better support for adults over forty. A supervised stress test beats every formula.
Do I need to enter my resting heart rate?
It is optional, but it changes the answer substantially and for the better. Without it the calculator uses plain percentages of maximum, which ignores where your heart starts from and under-prescribes for most people. With it, the zones are built from your own reserve.
What is heart rate reserve?
The gap between your maximum and your resting heart rate — the usable range your heart has. Someone with a maximum of 186 and a resting rate of 62 has a reserve of 124 beats. The Karvonen method scales percentages against that reserve rather than against the maximum.
Which zone should I train in?
Most of it should be easy. The light and moderate bands carry the bulk of endurance work, with harder efforts used sparingly in intervals. The frequent mistake is living in the middle — too hard to recover from, too easy to force adaptation. Keep easy days easy so the hard ones can be genuinely hard.
Why is my heart rate higher than usual at the same pace?
Usually heat, dehydration, poor sleep, a coming illness, caffeine, alcohol the night before, or altitude. Rate also drifts upward through any long session at constant effort. If it is well above normal for an easy pace, ease off rather than pushing to make the number fit.
What if I take beta blockers?
These targets do not apply. Beta blockers lower both resting and maximum heart rate, so the formulas here will overshoot your real range. Use perceived exertion instead, and ask the doctor who prescribed them what intensity is appropriate for you.
These zones are produced from population-average equations and are not a measurement of your heart or a personal exercise prescription. Individual maximum heart rates vary widely from any estimate, and the numbers here do not apply if you take beta blockers or other rate-controlling medication. Speak to a doctor before beginning vigorous exercise if you have a heart condition, high blood pressure, diabetes, a family history of early cardiac disease, are pregnant, or are returning to activity after a long break or serious illness. Stop exercising and seek medical help for chest pain or pressure, unusual breathlessness, dizziness, faintness, or an irregular heartbeat that does not settle. Learn more about how we build our calculators and read our privacy policy.