Your maximum heart rate (MHR) is the fastest your heart can beat during maximum exertion. It is the foundation of heart rate zone training — a method used by everyone from casual runners to Olympic athletes to target specific training adaptations.
The Old Formula (and Why It Is Outdated)
The most widely known formula is:
MHR = 220 − age
A 40-year-old would have an estimated MHR of 180 bpm. This formula is convenient and widely referenced — but it was never derived from scientific study. It was an informal observation from 1970 and has a standard deviation of ±10–12 bpm, meaning for a 40-year-old, the actual MHR could easily be anywhere from 168 to 192 bpm.
The Tanaka Formula (More Accurate)
A 2001 meta-analysis of 351 studies by Tanaka, Monahan, and Seals proposed the more accurate formula:
MHR = 208 − (0.7 × age)
| Age | 220−Age Formula | Tanaka Formula | Difference |
|---|---|---|---|
| 20 | 200 bpm | 194 bpm | −6 bpm |
| 30 | 190 bpm | 187 bpm | −3 bpm |
| 40 | 180 bpm | 180 bpm | 0 bpm |
| 50 | 170 bpm | 173 bpm | +3 bpm |
| 60 | 160 bpm | 166 bpm | +6 bpm |
| 70 | 150 bpm | 159 bpm | +9 bpm |
The Tanaka formula gives higher (more accurate) MHR estimates at older ages — important because underestimating MHR causes older adults to train at intensities lower than intended.
The 5 Heart Rate Training Zones
Once you know your MHR, you can calculate your five training zones as percentages:
| Zone | % of MHR | Name | Effect |
|---|---|---|---|
| Zone 1 | 50–60% | Recovery / Easy | Active recovery, warm-up |
| Zone 2 | 60–70% | Fat Burning / Aerobic base | Fat oxidation, endurance base |
| Zone 3 | 70–80% | Aerobic / Tempo | Aerobic capacity, sustained effort |
| Zone 4 | 80–90% | Threshold / Hard | Lactate threshold, race pace |
| Zone 5 | 90–100% | Maximum / Anaerobic | Speed, peak power output |
Example for a 35-year-old (Tanaka MHR = 184 bpm):
- Zone 1: 92–110 bpm
- Zone 2: 110–129 bpm
- Zone 3: 129–147 bpm
- Zone 4: 147–166 bpm
- Zone 5: 166–184 bpm
Which Zone Should You Train In?
For general health and fat loss: Zone 2 (60–70%) is the gold standard. It burns the highest proportion of fat as fuel and can be sustained for long durations without excessive recovery time. This is sometimes called "the aerobic base" that elite endurance athletes spend 80% of their training time in.
For improving cardiovascular fitness: Zone 3–4 training elevates your VO2 max and lactate threshold — the fitness markers most strongly associated with longevity.
For speed and power: Zone 5 intervals (sprints, HIIT) stimulate adaptations that Zone 2 cannot produce, but require more recovery time.
Resting Heart Rate: The Other Number
Your resting heart rate (RHR) is measured first thing in the morning before getting up. Normal range for adults: 60–100 bpm. Athletes often have RHRs of 40–60 bpm.
A declining resting heart rate over weeks and months is one of the clearest signals that your cardiovascular fitness is improving.
Calculate Your Heart Rate Zones
Our Heart Rate Calculator computes your MHR using multiple formulas and displays all five training zones with their bpm ranges — personalised to your age. Use it before any structured training programme.
Frequently Asked Questions
Q: Is "220 minus age" the best way to estimate max heart rate? A: Not really — it was never derived from a scientific study and has a standard deviation of ±10–12 bpm, so the Tanaka formula (208 − 0.7 × age), based on a 2001 meta-analysis of 351 studies, is more accurate, especially for older adults.
Q: What heart rate zone is best for fat loss? A: Zone 2 (60–70% of MHR) is the gold standard for fat burning, since it burns the highest proportion of fat as fuel and can be sustained for long periods — elite endurance athletes spend about 80% of their training time here.
Q: What is a normal resting heart rate, and what does a lower one mean? A: A normal resting heart rate for adults is 60–100 bpm, while athletes often sit at 40–60 bpm; a declining resting heart rate over weeks and months is one of the clearest signs that cardiovascular fitness is improving.
