Find your personalized training zones using the proven Karvonen formula. Train smart by knowing exactly when you're warming up, burning fat, or pushing toward maximum effort.
Enter your age and resting heart rate — zones update live.
Recommended Training Range
Max HR
190 bpm
Reserve (HRR)
125 bpm
Fat-Burn Mid
147 bpm
Aerobic Mid
159 bpm
Zone 1 – Warm Up
Very light · recovery, mobility
Zone 2 – Fat Burn
Easy · base building, fat oxidation
Zone 3 – Aerobic
Moderate · endurance, tempo
Zone 4 – Anaerobic
Hard · threshold, VO₂ work
Zone 5 – Max Effort
Very hard · short bursts only
| Zone | Intensity | Range (bpm) | Best For |
|---|
Typical Resting Heart Rates
Lower RHR generally indicates better cardiovascular fitness.
Training Tips
The Formula
We use the Karvonen formula — the gold standard for personalized training zones. Unlike a flat percentage of max heart rate, Karvonen accounts for your heart rate reserve: the gap between your resting and maximum heart rate.
A fitter person with a lower resting heart rate will get a different target than someone with the same age but a higher resting rate — even at the same training intensity.
Karvonen Equation
About This Tool
A target heart rate calculator tells you how fast your heart should beat during exercise for a specific training goal — fat loss, endurance, performance, or recovery. Most people unknowingly train at the wrong intensity, missing the benefits they're chasing.
This tool uses the Karvonen method, named after Finnish physiologist Martti Karvonen who developed it in the 1950s. It's more personalized than the simple "220 − age × %" approach because it factors in your resting heart rate — a strong proxy for cardiovascular fitness.
The result is five training zones spanning recovery to all-out effort. Knowing which zone you're in turns every workout into deliberate practice instead of guesswork — the difference between exercising and training.
Five Training Zones
From warm-up to max effort — every workout has a home.
Karvonen Accuracy
Uses heart rate reserve for more personalized targets.
Live Recalculation
Drag the sliders or type — every zone updates instantly.
Visual Range Chart
See all five zones side-by-side, scaled to your max HR.
Goal-Aware
Each zone is labeled with what it's best for — fat burn, endurance, VO₂.
Universal
Works for running, cycling, rowing, swimming — any aerobic activity.
Personalized training zones in under 30 seconds.
Take your pulse before you get out of bed on a few mornings and use the average. A fitness watch's resting reading also works.
Type or use the sliders. Both inputs feed into the Karvonen formula directly.
Each zone shows its bpm range and what it's best for — pick the one that matches your workout goal.
Use a chest-strap monitor for accuracy. Stay in your target zone for the bulk of the workout — drift out, drift back.
As you get fitter, resting HR drops. Re-run the calculator monthly to keep your zones accurate.
Most weeks: 80% Zones 1–2, 20% Zones 4–5. This polarized approach beats grinding in the middle.
The Karvonen formula
The Karvonen formula was published by Finnish physiologist Martti Karvonen in 1957. It sets training zones from your heart rate reserve (HRR), the gap between your maximum and resting heart rate. Because it accounts for your resting heart rate, it gives fitter people higher, more realistic zones than a simple percentage of maximum.
So this person's moderate zone (50–70%) is 120–144 bpm and their vigorous zone (70–85%) is 144–162 bpm. The fat-burning zone is usually quoted as 60–70% of HRR, which here is 132–144 bpm. The name comes from the higher share of energy drawn from fat at that intensity, not from burning more fat in total.
If you don't know your resting heart rate, the American Heart Association uses the simpler percentage-of-maximum method: 50–70% of MHR for moderate exercise and 70–85% for vigorous exercise.
| Age | Max HR (220 − age) | 50–85% target zone | 60–70% "fat burn" |
|---|---|---|---|
| 20 | 200 | 100–170 | 120–140 |
| 30 | 190 | 95–162 | 114–133 |
| 35 | 185 | 92–157 | 111–130 |
| 40 | 180 | 90–153 | 108–126 |
| 45 | 175 | 88–149 | 105–122 |
| 50 | 170 | 85–144 | 102–119 |
| 55 | 165 | 82–140 | 99–115 |
| 60 | 160 | 80–136 | 96–112 |
| 65 | 155 | 78–132 | 93–108 |
| 70 | 150 | 75–128 | 90–105 |
Karvonen vs % of max: for the same 40-year-old, 70% of max is 126 bpm but 70% of reserve is 144 bpm. Karvonen zones sit higher because they start from your resting rate. If you take beta-blockers or other heart-rate-lowering medication, these formulas don't apply. Ask your doctor for personal targets.
Turn your zones into energy numbers with the calories burned calculator, or plan a run at the right effort with the pace calculator.
Everything you need to know about heart rate training.
The Karvonen formula: Target HR = ((Max HR − Resting HR) × intensity%) + Resting HR. It uses your heart rate reserve, which makes it more personalized than the simpler "percent of max HR" method.
We use the classic 220 − age. Other formulas (Tanaka's 208 − 0.7 × age) can be slightly more accurate for older adults but differ by only a few bpm. The most accurate way is a maximal effort test under medical supervision.
Zone 2 (60–70% of heart rate reserve) burns the highest percentage of calories from fat, but Zones 3–4 burn more total calories, which usually wins for weight loss. For metabolic health and endurance, Zone 2 is the foundation; for time-efficient fat loss, mix in Zone 4 intervals.
Measure first thing in the morning before getting out of bed. Count beats for 60 seconds. Average over 3–5 mornings — daily values vary 5–10 bpm with sleep, stress and hydration. Typical adult RHR is 60–80 bpm; athletes often see 40–60 bpm.
These are estimates. If you have heart disease, take beta-blockers (which suppress HR), are new to exercise, or are over 40 and sedentary, consult a physician before training in higher zones. Chest pain, dizziness, or unusual breathlessness during exercise are reasons to stop immediately.
Wrist-based optical HR monitors typically read ±5 bpm and lag during quick intensity changes. Chest straps are the gold standard for accuracy — pick one if you do interval work. Many smartwatches use their own zone formulas (often %MHR rather than Karvonen), so the labels may differ.
For most goals, follow the polarized model: roughly 80% of your weekly minutes in Zones 1–2 (easy/conversational) and 20% in Zones 4–5 (hard intervals). The grey zone in the middle gets popular but produces the least adaptation per unit of fatigue.
This tool gives general health and fitness estimates. It is not medical advice, diagnosis or treatment. Talk to a doctor or registered dietitian before acting on the results, especially if you are pregnant, under 18 or managing a medical condition.
Spotted an error or out-of-date figure? Tell us. We review every report and correct confirmed mistakes promptly.