Target Heart Rate Zones
Calculate your five training heart-rate zones (50–100% of maximum) from your age and resting heart rate, using the Karvonen heart-rate-reserve method for more personalized targets. Use the zones to guide easy runs, endurance work, tempo efforts, and intervals.
How to Use
- Enter your age — the calculator estimates your maximum heart rate from it.
- Enter your resting heart rate in beats per minute, ideally measured first thing in the morning before getting up.
- Read your five training zones, each shown as a beats-per-minute range.
- Match the zone to your workout: easy recovery in zones 1–2, tempo in zone 3, threshold and hard intervals in zones 4–5.
- Try the presets, including the endurance-athlete option with a low resting heart rate, to see how fitness shifts the zones.
Show Work
Zones
About the Target Heart Rate Zones
The Target Heart Rate Zones gives you a fast, free answer for health and fitness tracking without sending anything off your device. Calculate your five training heart-rate zones (50–100% of maximum) from your age and resting heart rate, using the Karvonen heart-rate-reserve method for more personalized targets. Use the zones to guide easy runs, endurance work, tempo efforts, and intervals.
How it works
Enter your figures and the result appears instantly, updating the moment you change anything. There is no submit button and nothing to wait for, so it is easy to try a few what-if numbers and compare the results. Just check each box holds the kind of value it expects.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How is maximum heart rate estimated?
This calculator uses the Tanaka formula, 208 − (0.7 × age), which research found to be more accurate across ages than the older 220 − age rule. Both are population averages, so your true maximum can be 10–20 beats per minute higher or lower. A lab test or a maximal-effort field test gives a more precise figure if you need one.
What is the Karvonen method and why use resting heart rate?
The Karvonen method calculates target zones from your heart-rate reserve — the gap between your maximum and resting heart rate — rather than from maximum alone. The target for a given intensity is resting HR + (percentage × reserve). Because it factors in your resting rate, it produces more individualized zones, which is why fitter people with low resting rates get different targets.
What are the five training zones for?
Roughly: Zone 1 (50–60%) is active recovery, Zone 2 (60–70%) builds aerobic endurance and fat-burning, Zone 3 (70–80%) is a moderate tempo effort, Zone 4 (80–90%) is near your lactate threshold for hard sustained work, and Zone 5 (90–100%) is maximal interval territory. A balanced program spends most time in the lower zones with smaller doses of the top ones.
How do I measure my resting heart rate accurately?
Measure it when you're fully rested — ideally right after waking, before caffeine or activity. Count your pulse for 60 seconds, or use a wearable that tracks overnight resting heart rate. Take it on a few mornings and average them, since a single reading can be affected by poor sleep, stress, or illness.
Are these zones safe for everyone?
The zones are general estimates for healthy adults and are provided for informational and educational purposes only — not medical advice. Medications (such as beta-blockers), heart conditions, and individual variation can all affect your true heart-rate response. If you have any cardiovascular concerns or are starting exercise after a long break, consult a doctor before training to heart-rate targets.
How do I use the Target Heart Rate Zones?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Does it cost anything or need an account?
No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.
Is anything I type uploaded?
No. The tool works entirely on your device, so the values you enter never leave your browser.
Common Use Cases
Structuring cardio workouts
Pick the right zone for recovery, endurance, tempo, or interval sessions.
Polarized training
Identify your zone 2 ceiling to keep easy days truly easy and hard days hard.
Setting watch alerts
Program the beats-per-minute ranges into a fitness watch to stay in the intended zone.
Tracking fitness gains
Recalculate as your resting heart rate drops to see your zones shift with improved fitness.
Pacing group or class workouts
Translate intensity cues like "moderate" or "hard" into personal heart-rate targets.
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