Audited —·Last updated 27 Jul 2026·7 citations·Tier 1·0 uses

Target Heart Rate Calculator

Free target heart rate calculator using Karvonen and %MaxHR with Tanaka or Fox max HR formulas. Find your training zone in beats per minute.

Target Heart Rate Calculator

Your current age in whole years (10–100).
years
Measure first thing in the morning while still in bed. Enter 0 if unknown — we'll fall back to %MaxHR.
bpm
50–60% warm-up, 60–70% fat-burn, 70–80% cardio/aerobic, 80–90% anaerobic threshold.
%
Max Heart Rate Formula
Target HR Method
Target Heart Rate
149
The heart rate you should aim for at your chosen intensity.
Maximum Heart Rate
187 bpm
Heart Rate Reserve
127 bpm
Method Used
1

Background.

This target heart rate calculator turns a single training intensity goal into a precise beats-per-minute number you can chase on a chest strap, watch, or treadmill console. It supports the two formulas that actually matter in modern exercise physiology: the Karvonen heart rate reserve method, which factors in your resting heart rate to personalise the zone, and the simpler %MaxHR method that scales straight off your age-predicted maximum. For the maximum itself, you can pick the classic Fox equation (220 − age, the one printed on every gym poster) or the more accurate Tanaka 2001 revision (208 − 0.7 × age) published in the Journal of the American College of Cardiology after pooling data from 351 studies and 18,712 subjects.

Tanaka is the better default. Fox systematically overestimates maximum heart rate for people under 40 and underestimates it for adults over 40, and the standard deviation of Fox at any given age is roughly 12 bpm — wide enough to push you a full training zone in the wrong direction. Tanaka cuts that error nearly in half and is now the equation the American College of Sports Medicine cites in its Guidelines for Exercise Testing and Prescription.

Why does the choice of method matter? Two runners aged 30 with the same age-predicted max of 187 bpm can have very different resting heart rates — a deconditioned office worker might sit at 78 bpm, a trained endurance athlete at 45 bpm. Plug both into a 70% intensity target. The %MaxHR method gives them both the same number: 131 bpm. The Karvonen method gives the office worker 154 bpm and the athlete 144 bpm. That gap is not noise — it is the entire reason heart rate reserve was invented. Martti Karvonen showed in 1957 that training adaptations track heart rate reserve (max minus resting) far more tightly than they track raw percentages of maximum, because reserve is the actual range your cardiovascular system can recruit.

The five intensity zones used by ACSM, AHA, and most coaching organisations map cleanly onto this calculator. Zone 1 (50–60% of HRR or MaxHR) is warm-up and active recovery — easy nasal breathing, full conversation. Zone 2 (60–70%) is the fat-oxidation and aerobic base zone where most endurance volume should sit; you can speak in full sentences but not sing. Zone 3 (70–80%) is the cardio or tempo zone — short sentences, breathing noticeably harder. Zone 4 (80–90%) is the anaerobic threshold zone where lactate accumulates faster than it clears; you can manage only a few words at a time. Zone 5 (90–100%) is the VO2 max and neuromuscular zone, sustainable for seconds to a couple of minutes.

To use the calculator, enter your age, your resting heart rate measured first thing in the morning before you sit up (a wrist-worn tracker or 30-second manual pulse count over the carotid both work), the intensity percentage of the zone you want to train in, the maximum heart rate formula, and which method to apply. If you leave resting heart rate at zero the calculator automatically falls back to %MaxHR, since Karvonen needs the resting value to compute the reserve.

One important caveat: any age-predicted formula is a population estimate, not a personal measurement. If you take beta-blockers, calcium channel blockers, or other heart-rate-suppressing medications, the predicted maximum will overshoot your actual ceiling by 20–30 bpm — ask your cardiologist for a graded exercise test instead. The same applies if you have a pacemaker, atrial fibrillation, or known coronary disease. For everyone else, pair the number this calculator gives you with the talk test as a sanity check, log your sessions for a few weeks, and adjust the percentage up or down until perceived exertion matches the zone description.

What is target heart rate calculator?

Target heart rate is the beats-per-minute range you aim to keep your heart in during cardiovascular exercise to elicit a specific physiological adaptation — fat oxidation, aerobic base, lactate threshold, or VO2 max. It is calculated from your maximum heart rate (the highest rate your heart can sustain for a few seconds at all-out effort) scaled by the percentage intensity of the zone you want to train. The two dominant methods are Karvonen, which uses heart rate reserve (max minus resting), and percent of maximum heart rate, which uses max alone.

How to use this calculator.

  1. Enter your age in whole years.
  2. Measure your resting heart rate in the morning before getting out of bed — count your pulse for 30 seconds and double it, or read it from a chest strap or wrist tracker.
  3. Pick the training intensity percentage for the zone you want — 60% for fat-burn, 70% for steady cardio, 80% for tempo, 85%+ for threshold work.
  4. Choose Tanaka 2001 as the max heart rate formula unless a coach has told you to use Fox.
  5. Leave method on Auto — it picks Karvonen when you provide a resting heart rate and %MaxHR when you don't.
  6. Read the target heart rate output and aim for ±5 bpm during the steady portion of your workout.

The formula.

THR = (HRmax − HRrest) × I + HRrest
THR · target heart rate (bpm)HRmax · 208 − 0.7 × age (Tanaka)HRrest · resting heart rateI · chosen intensity fractionKarvonen shown · %MaxHR = HRmax × I

There are two layers to the calculation. Layer one is maximum heart rate. Tanaka 2001: maxHR = 208 − 0.7 × age. Fox 1971: maxHR = 220 − age. Layer two is the target heart rate at a chosen intensity. The Karvonen method uses heart rate reserve: HRR = maxHR − restingHR, then target = HRR × intensity + restingHR. This adds resting heart rate back in so the bottom of the range never falls below where your heart already idles. The %MaxHR method skips reserve entirely: target = maxHR × intensity. Karvonen produces higher numbers than %MaxHR at any given intensity because resting heart rate is added back in at the end. Both methods are valid; ACSM recommends Karvonen when resting heart rate is known because it correlates more tightly with VO2 reserve, the gold-standard measure of relative exercise intensity.

A worked example.

Example

A 30-year-old runner with a resting heart rate of 60 bpm wants to find her target heart rate for steady aerobic work at 70% intensity using Karvonen and Tanaka. Step 1: maxHR = 208 − 0.7 × 30 = 208 − 21 = 187 bpm. Step 2: heart rate reserve = 187 − 60 = 127 bpm. Step 3: target = 127 × 0.70 + 60 = 88.9 + 60 = 148.9, rounded to 149 bpm. She will aim to hold her heart rate at roughly 149 bpm during the main set, allowing a ±5 bpm drift for terrain and temperature. If she had used %MaxHR instead, the answer would have been 187 × 0.70 = 131 bpm — 18 beats lower, which would actually be a Zone 2 fat-burn pace for her rather than the Zone 3 aerobic effort she intended.

resting Hr60
methodkarvonen
intensity Percent70
max Hr Formulatanaka
age30

Frequently asked questions.

Karvonen formula vs %MaxHR — which one should I use?
Use Karvonen if you know your resting heart rate. It produces a more personalised number because it accounts for your cardiovascular baseline through heart rate reserve, and it correlates more closely with VO2 reserve, which is what exercise physiologists actually want intensity to track. Use %MaxHR only when resting heart rate is unknown — it is simpler but ignores the fact that two people with the same max can have very different working ranges. ACSM's 11th edition Guidelines for Exercise Testing and Prescription recommend Karvonen as the default in clinical and coaching settings.
When should I use the Fox formula (220 − age) instead of Tanaka?
Almost never. Fox 1971 was originally a casual approximation in a review paper, not a published equation derived from data. Tanaka 2001 pooled 351 studies and 18,712 subjects and produced 208 − 0.7 × age with a standard deviation roughly half of Fox's. The only reasons to pick Fox are (1) you are following a published training plan that explicitly references it, or (2) you are over 40 and want the lower estimate Tanaka gives you, but in that case you should still use Tanaka — it is the more accurate one for your age group. Fox actually overestimates max HR for older adults.
Why does resting heart rate matter for training zones?
Because two people with identical maximum heart rates can have wildly different reserves. A trained athlete might rest at 45 bpm and a sedentary peer at 75 bpm — same age, same max, but the athlete has 30 more beats of usable range. Karvonen captures that by computing the reserve and scaling intensity off it. Without resting heart rate, %MaxHR puts both people at the same target, which understates the athlete's working capacity and overstates the sedentary person's. A 2018 meta-analysis in the European Journal of Applied Physiology confirmed Karvonen tracks VO2 reserve more tightly than %MaxHR across fitness levels.
How do I find my resting heart rate accurately?
Measure first thing in the morning while still lying supine in bed, before reaching for your phone or sitting up. Either count the pulse on your wrist or carotid for 60 seconds, or read the value off a chest strap or wrist-worn optical sensor. Do this on three consecutive mornings and average the results — single readings can be skewed by a noisy night, alcohol, or an early-stage cold. Avoid measuring after coffee, exercise, or stressful news. Most healthy adults sit between 60 and 80 bpm; trained endurance athletes can sit between 35 and 55 bpm.
What are the five heart rate training zones?
Zone 1 (50–60%) — warm-up and recovery, conversational. Zone 2 (60–70%) — aerobic base and fat oxidation, full sentences possible, sustainable for hours. Zone 3 (70–80%) — aerobic/cardio tempo, short sentences only. Zone 4 (80–90%) — anaerobic threshold, only a few words at a time, lactate begins to accumulate. Zone 5 (90–100%) — VO2 max and neuromuscular, seconds to two minutes maximum. Most endurance athletes spend 80% of weekly volume in Zone 2, the rest split across higher zones — the so-called polarised model popularised by Stephen Seiler.
I take beta-blockers — is this calculator accurate for me?
No. Beta-blockers, calcium channel blockers, and certain antiarrhythmics blunt the sympathetic nervous system's effect on the heart, lowering both maximum and submaximal heart rate by 20–30 bpm. The age-predicted formulas assume an untreated cardiovascular system. If you are on these medications, ask your cardiologist for a graded exercise stress test to measure your true peak heart rate, then build zones off that observed value. The same applies if you have a pacemaker, atrial fibrillation, or use chronotropic medications — the AHA recommends supervised testing in those populations before setting training targets.
What if I don't have a heart rate monitor — can I use the talk test instead?
Yes, the talk test is a validated proxy that maps cleanly onto ventilatory thresholds. Zone 1–2: you can hold a full conversation in complete sentences. Zone 3: you can speak in short sentences but breathing is noticeably elevated. Zone 4: only a few words at a time. Zone 5: single words or none. A 2014 study in the International Journal of Sports Medicine showed the talk test correlates with the first and second ventilatory thresholds with roughly the same accuracy as a 70–85% MaxHR window. Use the talk test as a sanity check even when wearing a monitor — if the watch says Zone 3 but you can sing, the strap is probably misreading.
Why is my measured max heart rate different from the age-predicted one?
Because both Tanaka and Fox are population averages, not individual measurements. The standard deviation around the Tanaka estimate is roughly 7 bpm and around Fox is 12 bpm — meaning your true max could legitimately be 15–25 bpm above or below the formula. If you have done a true max-effort test (a 4 × 4 minute interval workout with a final all-out push, or a graded treadmill test) and your watch recorded a higher peak, use that measured number as your max in subsequent zone calculations. Measured beats predicted every time.
How often should I recalculate my target heart rate?
Recalculate annually, after any significant change in resting heart rate (a drop of 5+ bpm typically indicates improved aerobic conditioning), after starting or stopping cardiovascular medications, and after any extended layoff. Maximum heart rate declines slowly — roughly 0.7 bpm per year per Tanaka — so age-driven recalculation matters more across decades than across single years. Resting heart rate, by contrast, can shift meaningfully in 8–12 weeks of consistent training, so review your zones each season.
Does heart rate variability (HRV) replace target heart rate zones?
No, they answer different questions. Target heart rate tells you how hard to push during a workout. HRV tells you whether you are recovered enough to push hard today. Modern athletes use both: HRV trends inform the daily decision to train hard, take a recovery day, or back off, while heart rate zones inform the structure of the workout once you start. Tools that combine the two — Polar's training load, Garmin's body battery, Whoop's strain — are essentially layering HRV-based readiness on top of a zone-based prescription.

References& sources.

  1. [1]Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate; a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniae. 1957;35(3):307-315. (Original heart rate reserve / Karvonen method paper.)
  2. [2]Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology. 2001;37(1):153-156.
  3. [3]Fox SM III, Naughton JP, Haskell WL. Physical activity and the prevention of coronary heart disease. Annals of Clinical Research. 1971;3(6):404-432. (Original Fox 220 − age estimate.)
  4. [4]American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription, 11th edition, Chapter 6: General Principles of Exercise Prescription. Wolters Kluwer, 2021. ISBN 978-1-975150-58-3.
  5. [5]American Heart Association. Target Heart Rates Chart. Updated 2022.
  6. [6]Lounana J, Campion F, Noakes TD, Medelli J. Relationship between %HRmax, %HR reserve, %VO2max, and %VO2 reserve in elite cyclists. Medicine & Science in Sports & Exercise. 2007;39(2):350-357.
  7. [7]Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance. 2010;5(3):276-291. (Polarised training and zone distribution.)
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