Heart rate zones calculator for Zone 2, tempo, threshold, and VO2 max.
Use age, an optional resting heart rate, and a chosen max-heart-rate formula to estimate training zones for recovery, aerobic base, tempo, threshold, and VO2-max work. If you only care about aerobic-base work, the dedicated Zone 2 page sits one step deeper.
Best use case
Structuring easy, moderate, threshold, and top-end cardio sessions more deliberately.
Biggest caveat
All age-based zone systems are still estimates unless you have tested values.
Best follow-up
Put the training intensity inside real calorie and recovery planning instead of using it alone.
Build training zones that actually match the workout goal.
Use age, an optional resting heart rate, and a chosen max-heart-rate formula to estimate heart-rate zones for recovery work, aerobic base, tempo, threshold, and VO2-max sessions.
Best measured after waking, before getting out of bed.
Start with age, then layer in resting heart rate if you know it.
The calculator gives a fast zone estimate either way, but resting heart rate makes the Karvonen version more personalized.
Each zone is useful for a different reason
The main point of zones is not to make every workout look technical. It is to stop recovery work, base work, tempo work, and hard intervals from bleeding into each other until they all feel vaguely medium-hard.
Zone 1
Recovery and very easy aerobic work. Best for warm-ups, cool-downs, and low-stress volume.
Zone 2
Aerobic-base work. Often the most useful zone for building repeatable endurance with manageable recovery.
Zone 3
Moderate tempo work. Useful, but easy to overuse because it feels productive without being easy enough or hard enough.
Zones 4 and 5
Threshold and VO2-max work. High-value for speed and power, but only when used deliberately and sparingly.
The method matters because the estimate matters
The biggest error is often not the exact bpm line. It is using an estimation method that does not fit the quality of the data you actually have.
Karvonen / heart-rate reserve
Usually the more personalized choice because it uses resting heart rate instead of relying only on max-heart-rate estimates.
Simple percentage
Useful as a quick first pass when you know your age or max heart rate but not your resting value.
Tanaka vs 220-age
The Tanaka formula is often a better default estimate than the older 220-minus-age shortcut.
The training win is cleaner intensity distribution
A lot of cardio stalls because everything lands in the same medium-hard zone. The zones are there to protect easy work, give hard work its own place, and stop one session type from pretending to be five.
Keep easy work easy
The most common training mistake is turning recovery or base days into medium-hard slogs that are too hard to recover from and too easy to drive real adaptation.
Use Zone 2 for repeatable volume
Zone 2 is popular for a reason: it is one of the easiest places to build cardiovascular work without paying a huge recovery price.
Earn the hard zones
Zones 4 and 5 help most when they sit on top of real aerobic work, not when every session becomes a threshold or HIIT workout.
App Next
Use the zones for training. Use the app for the rest of the day.
Heart-rate zones help structure cardio, but training intensity is still only one part of the plan. Use the Calorie Calculator app to keep meals, calories, and macros visible so zone work fits the day instead of floating beside it.
Download
Use the browser tool for intensity planning, then use the app on iPhone or Android for the repeat meal-tracking job.
Frequently Asked Questions
What is the best method for heart rate zones?
What is Zone 2 heart rate?
Is 220 minus age accurate?
Should all cardio be done in Zone 2?
How often should I update my zones?
Research and reference notes
Foundational paper on heart-rate reserve and the training response to heart rate.
Important revision of age-predicted maximal heart-rate formulas.
Endurance-training review supporting polarized distribution and clear intensity separation.