Heart Rate Zones Calculator
Calculate your five heart rate training zones using your choice of max HR formula. Get bpm ranges for each zone, their training purposes, and a visual chart — all for free.
What Are Heart Rate Zones?
Heart rate zones are ranges of heartbeats per minute (bpm) that correspond to different exercise intensities. Training in specific zones lets you target particular physiological adaptations — from recovery and fat oxidation to maximal speed. Most systems use five zones, each defined as a percentage of your maximum heart rate (HRmax).
This calculator computes your zones using your choice of max HR formula and, optionally, the more personalized Karvonen method (which uses your resting heart rate).
The Five Heart Rate Zones
Zone 1 — Recovery (50–60% HRmax): Very light effort. Warm-up, cool-down, and active recovery. You can hold a full conversation.
Zone 2 — Aerobic Base (60–70% HRmax): Light to moderate effort. Builds endurance and improves fat oxidation. You can speak in full sentences but may need to pause for breath.
Zone 3 — Tempo (70–80% HRmax): Moderate to hard effort. Improves aerobic capacity and muscular strength. Conversation requires effort.
Zone 4 — Threshold (80–90% HRmax): Hard effort. Boosts speed and lactate threshold. Talking is difficult; short phrases only.
Zone 5 — Maximum (90–100% HRmax): Very hard, near-maximal effort. Used for short intervals to develop peak power and speed. Cannot speak.
These percentages follow the widely used % of Max HR model. Some systems (e.g., WHOOP) shift the boundaries slightly, but the five-zone structure is consistent across most training platforms.
Max Heart Rate Formulas Used
The calculator offers four age-based formulas for estimating HRmax:
Fox (220 − age): The classic, most widely used formula. Simple but has a standard error of about 10–15 bpm.
Tanaka (208 − 0.7 × age): Derived from a large meta-analysis (18,712 individuals). More accurate than Fox, especially for older adults.
Gulati (206 − 0.88 × age): Developed specifically for women from the St. James Women Take Heart Project. More accurate for female users.
Nes (211 − 0.64 × age): From the Norwegian HUNT study. Considered among the most accurate population-level formulas for mixed-sex adults.
Karvonen Method (Heart Rate Reserve)
If you provide your resting heart rate, you can switch to the Karvonen method, which is more personalized because it accounts for your individual fitness level:
Heart Rate Reserve (HRR) = HRmax − Resting HR
Target HR = (HRR × intensity%) + Resting HR
For example, Zone 2 (60–70%) uses 60–70% of your heart rate reserve, added back to your resting HR.
The Karvonen method is generally preferred by endurance athletes and coaches because it reflects your actual cardiovascular fitness rather than just your age.
Why Use This Heart Rate Zones Calculator?
- Choice of max HR formula: Fox, Tanaka, Gulati (women-specific), or Nes.
- Karvonen option: Personalize your zones using your resting heart rate.
- Clear bpm ranges: See the exact heart rate range for each of the five zones.
- Zone purposes: Understand what each zone is for, so you can train with intent.
- Visual chart: A bar chart shows your zones side by side.
- Free & Private: No registration, no data storage.
Understanding Your Results
- Maximum Heart Rate (HRmax): The highest heart rate you can achieve during all-out effort. Estimated from your age (or measured in a lab/field test).
- Heart Rate Reserve (HRR): The difference between your max HR and resting HR. A larger HRR generally indicates better cardiovascular fitness.
- Zone boundaries: Calculated as percentages of HRmax (or HRR). A higher resting HR shifts the zones upward in the Karvonen method.
Note: Age-based formulas are estimates. For precise training zones, a maximal effort test or lab-based VO₂ max test is more accurate. Consult a healthcare professional before starting a high-intensity training program.
❓ Heart Rate Zones Calculator FAQ
What are the 5 heart rate zones?
The five zones are: Zone 1 (50–60% HRmax, recovery), Zone 2 (60–70%, aerobic base), Zone 3 (70–80%, tempo), Zone 4 (80–90%, threshold), and Zone 5 (90–100%, maximum). Each zone targets different physiological adaptations.
Which max heart rate formula is most accurate?
Tanaka and Nes are generally more accurate than Fox for adults. Gulati is the best choice for women. Fox remains the most widely used because of its simplicity, but it can be off by 10–15 bpm for an individual.
What is the Karvonen method?
The Karvonen method calculates target heart rate as a percentage of your heart rate reserve (HRmax − resting HR), added to your resting HR. It's more personalized than using a simple percentage of HRmax because it accounts for your fitness level.
What is Zone 2 training and why is it popular?
Zone 2 (60–70% HRmax) is the "aerobic base" zone. It builds endurance, improves fat oxidation, and is sustainable for long periods. Many endurance athletes spend the majority of their training time in Zone 2 to build a strong aerobic foundation without excessive fatigue.
How do I find my resting heart rate?
Measure your pulse for 60 seconds immediately after waking up, before getting out of bed. Do this for several days and average the results. A typical adult resting HR is 60–100 bpm; fit individuals often have values in the 40s–50s.
Is the "fat-burning zone" real?
The idea that low-intensity exercise burns a higher percentage of calories from fat is true, but higher-intensity exercise burns more total calories and often more total fat. The "fat-burning zone" is not magic — overall calorie balance drives fat loss.
Can I use these zones for running, cycling, and other sports?
Yes. Heart rate zones are sport-agnostic because they are based on your cardiovascular system's response. However, your max HR can differ slightly between sports (e.g., running vs. cycling), so sport-specific testing is more precise.
How often should I recalculate my zones?
Recalculate every few months, or when your age, resting heart rate, or fitness level changes significantly. Age-based max HR decreases gradually, so annual recalculation is usually sufficient for most people.
What if my heart rate feels higher than the zone suggests?
Age-based formulas are estimates. Factors like caffeine, heat, stress, medication, and individual physiology can shift your heart rate. Use the zones as a guide, not an absolute rule, and pay attention to perceived effort (RPE) alongside heart rate.
Can I use this calculator if I take beta-blockers?
Beta-blockers lower heart rate, so standard age-based formulas will overestimate your zones. You need a personalized assessment, ideally with a cardiologist or exercise physiologist, to set accurate training zones.
What is heart rate reserve (HRR)?
HRR = HRmax − resting HR. It represents the range of heart rates available for exercise. A larger HRR indicates better cardiovascular fitness, which is why the Karvonen method uses HRR for more personalized zone calculation.
How do I convert measurements between metric and imperial?
This calculator doesn't require height or weight — only age, resting heart rate, and gender (for the Gulati formula). Heart rate is always expressed in beats per minute (bpm).