Heart Rate Zone Calculator
This heart rate zone calculator turns your maximum heart rate — from your age or a measured value — into five training zones. Add a resting heart rate to switch to the Karvonen heart-rate-reserve method for more personal targets.
How it works
Start with your maximum heart rate. The simplest estimate is 220 − age; the Tanaka formula (208 − 0.7 × age) fits the wider population a little better. Best of all is a measured max from an all-out effort, which you can type in directly.
The five zones are then drawn as percentage bands of that maximum. If you also enter a resting heart rate, the calculator switches to the Karvonen formula, which works from your heart-rate reserve (max − rest):
target bpm = (max − rest) × % + rest
Karvonen shifts the zones upward because it anchors the bottom of the range to your resting pulse rather than to zero, so it tends to reflect fitness better than a plain percentage of max.
Worked example
Take a 30-year-old. Estimated max heart rate is 220 − 30 = 190 bpm. Using the percentage-of-max method, Zone 2 (60–70%) is 190 × 0.6 to 190 × 0.7 ≈ 114–133 bpm.
Now add a resting heart rate of 60 bpm and switch to Karvonen. Heart-rate reserve is 190 − 60 = 130. Zone 2 becomes 130 × 0.6 + 60 to 130 × 0.7 + 60 ≈ 138–151 bpm — noticeably higher than the plain percentage version.
The five heart rate zones
Each zone is a band of your maximum heart rate:
| Zone | % of max HR | Purpose |
|---|---|---|
| Z1 · Recovery | 50–60% | Very light effort for warm-ups, cool-downs and active recovery. |
| Z2 · Easy / Endurance | 60–70% | Conversational base mileage; builds aerobic fitness and fat use. |
| Z3 · Aerobic / Tempo | 70–80% | Moderate, steady effort that improves aerobic capacity. |
| Z4 · Threshold | 80–90% | Hard, sustainable effort near lactate threshold; raises speed. |
| Z5 · Maximal | 90–100% | All-out intervals for top-end power and VO₂ max. |
Using the zones
Most endurance plans keep the bulk of training easy (Zones 1–2) and reserve hard efforts (Zones 4–5) for a smaller share of total time. If you train mostly by feel, the Max Heart Rate Calculator and a chest-strap monitor help you check that your easy days are genuinely easy. To plan the sessions themselves, the Pace Calculator converts target effort into splits.
Frequently asked questions
What are heart rate zones?
- Heart rate zones are five effort bands defined as percentages of your maximum heart rate (or heart-rate reserve). Each zone — from recovery to maximal — targets a different training adaptation, so spending time in the right zone makes workouts more effective.
How do I calculate my max heart rate?
- The classic estimate is 220 minus your age, so a 30-year-old has an estimated max of about 190 bpm. The Tanaka formula (208 − 0.7 × age) fits the population better. For the most accurate value, use a measured maximum from an all-out test.
What is the Karvonen formula?
- The Karvonen method uses your heart-rate reserve — maximum heart rate minus resting heart rate. A target is reserve × percentage + resting HR. Because it accounts for fitness via your resting pulse, it gives more individualised zones than a plain percentage of max.
Which zone burns the most fat?
- Lower zones (roughly Zone 2, 60–70% of max) burn the largest share of calories from fat, which is why it is called the fat-burning zone. Higher zones burn more total calories overall, so total energy expenditure matters more than the fat percentage for fat loss.
How accurate is 220 minus age?
- It is a quick estimate with a wide spread — individual maximums can differ by 10–20 bpm or more. Use it as a starting point, prefer the Tanaka formula for population accuracy, and replace it with a measured maximum when you have one.
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Disclaimer. These zones are estimates for general fitness use, not medical advice. Age-predicted maximums vary widely between individuals. Consult a doctor before starting intense exercise, especially if you have a heart condition or other health concerns.