Heart Rate Zone Calculator

Use our free heart rate zone calculator to find your five training zones. It shows both methods side by side, Karvonen and percentage of max, so you can see how much your resting heart rate changes the answer. Enter your current heart rate to check which zone you are in.

What Are Heart Rate Zones?

Heart rate zones are five intensity bands, each defined as a percentage of your maximum heart rate or heart rate reserve. Each zone trains a different system. Zone 1 is recovery, Zone 2 builds your aerobic base and fat metabolism, Zone 3 is tempo work, Zone 4 is lactate threshold, and Zone 5 is peak power. Training without zones is guesswork: most people go too hard on easy days and too easy on hard days.

How This Heart Rate Zone Calculator Works

First, this heart rate zone calculator estimates your maximum heart rate from your age. You can choose Tanaka (208 – 0.7 x age), which comes from a 2001 meta-analysis of 351 studies and is more accurate especially over 40, Fox (220 – age), which is simpler but can be off by 10 to 12 bpm, Nes (211 – 0.64 x age), or your own measured max from a real test.

Then it applies two methods. The percentage-of-max method multiplies your max heart rate by the zone percentage. The Karvonen method uses heart rate reserve: Target = Resting + (Max – Resting) x intensity. Karvonen accounts for fitness, because two people with the same max but different resting heart rates get different zones. The two methods can disagree by 15 to 20 bpm in Zone 2, which is why most people train Zone 2 wrong.

ZoneNameIntensityEffortTraining focus
Zone 1Recovery50-60%Very lightEasy chat, recovery, warm-up
Zone 2Endurance60-70%LightFull sentences, aerobic base, fat metabolism
Zone 3Tempo70-80%ModerateShort sentences, aerobic capacity
Zone 4Threshold80-90%HardFew words, lactate threshold, speed
Zone 5VO2 Max90-100%MaximumCannot talk, peak power, short intervals

Source: 2001 meta-analysis of 351 studies (Tanaka et al.).

Worked Example

In this heart rate zone calculator example, take a 30-year-old with a resting heart rate of 60 bpm using Tanaka. Max HR is 208 – 0.7 x 30 = 187 bpm, and heart rate reserve is 187 – 60 = 127 bpm. Karvonen zones are Zone 1 124 to 136, Zone 2 136 to 149, Zone 3 149 to 162, Zone 4 162 to 174, and Zone 5 174 to 187 bpm. Percentage-of-max zones are Zone 1 94 to 112, Zone 2 112 to 131, Zone 3 131 to 150, Zone 4 150 to 168, and Zone 5 168 to 187 bpm.

If that same person enters a current heart rate of 145 bpm, intensity is (145 – 60) / 127 x 100 = 67%, which is Zone 2. That is the reverse lookup: the calculator tells you which zone your current heart rate falls in.

Common Heart Rate Zone Problems (And How to Fix Them)

  • Watch says Zone 2 but feels too easy: most watches use percentage of max, which underestimates Zone 2 for fit people. Switch to Karvonen with your real resting heart rate. If it still feels too easy, your max estimate may be low.
  • Two calculators give different Zone 2 ranges: different methods or max formulas cause this. Compare the method, not just the number. Karvonen with Tanaka is the most defensible default.
  • Heart rate high on a hot day at the same pace: heat, dehydration, poor sleep, and illness raise heart rate. Train by feel and perceived effort on those days.
  • Cannot stay in Zone 2, even walking pushes me out: common for beginners. Walk slower, avoid hills, and use walk-run intervals. Your aerobic base improves fast.
  • Resting heart rate keeps changing: measure first thing in the morning before coffee, lying down, and average three mornings.

How to Train With Your Zones

Follow an 80/20 split: about 80% of your weekly training time in Zones 1 and 2, 20% in Zones 4 and 5, and Zone 3 sparingly. Zone 2 builds mitochondria and capillaries, improves fat metabolism, and lets you recover fast. Add 1 to 2 hard sessions a week in Zones 4 and 5. Recalculate your zones every 3 to 6 months as your resting heart rate drops.

Use this heart rate zone calculator to check your zones before you start a new training block.

To plan your fueling around training, use our TDEE calculator and macro calculator to estimate your daily energy and macronutrient needs.

Frequently Asked Questions

What are the 5 heart rate zones?

Zone 1 Recovery 50-60%, Zone 2 Endurance 60-70%, Zone 3 Tempo 70-80%, Zone 4 Threshold 80-90%, Zone 5 VO2 Max 90-100% of max or heart rate reserve.

What is the best heart rate zone for fat burning?

Zone 2 burns the highest percentage of fat, but total calories matter more than the percentage. Zone 2 is still the best default because you can sustain it for long sessions.

What is the Karvonen formula?

Target HR = Resting HR + (Max HR – Resting HR) x intensity. It personalizes zones using your resting heart rate, unlike the plain percentage-of-max method.

Which max heart rate formula is most accurate?

Tanaka (208 – 0.7 x age) comes from a meta-analysis of 351 studies and is generally more accurate than 220 – age, especially over 40. A measured max from a real test beats any formula.

How do I find my resting heart rate?

Measure first thing in the morning, before coffee, lying down, and average three mornings. Wrist watches give a decent estimate if worn overnight.

What heart rate zone should I train in most?

Zone 2, about 80% of your weekly training time. It builds your aerobic base. Add 1-2 hard sessions in Zones 4-5 per week.

Why does my Zone 2 feel different from my friend’s?

Because resting heart rate and max heart rate differ between people. Same age does not mean same zones, which is why Karvonen exists.

Can heart rate zones be wrong?

Yes. Age formulas are averages with about 10-15 bpm of individual variation, and heat, sleep, and illness shift heart rate daily. Cross-check with perceived effort.

How often should I recalculate my zones?

Every 3-6 months, or whenever your resting heart rate changes noticeably. As fitness improves, resting HR drops and zones shift.

Other Calculators