What are my heart rate zones at age 40?

At 40 the Tanaka formula gives a maximum of 180 bpm, so the zones are 90 to 108 bpm (Zone 1), 108 to 126 (Zone 2), 126 to 144 (Zone 3), 144 to 162 (Zone 4), and 162 to 180 (Zone 5). Results are estimates for informational purposes only.

Which zone burns the most fat?

The share of energy from fat is highest at easy efforts in Zones 1 and 2, and fat burned per minute usually peaks near the top of Zone 2 or the bottom of Zone 3. Zones 3 and 4 burn more total calories per minute, and for weight loss total energy use matters more than the fuel mix.

How much time should I spend in each zone?

Most endurance coaches recommend the 80/20 rule: 80% of training in Zone 1–2 (low intensity) and 20% in Zone 3–5 (higher intensity). This approach builds aerobic base while avoiding overtraining.

Does the calculator work offline?

Once the page has loaded, yes. The formula runs in the open tab, so it keeps working if your connection drops. Reloading or opening another page needs a connection again.

Heart rate zones by age

Enter your age to see five heart rate training zones set as fixed shares of your estimated maximum heart rate, from 50 to 60 percent for recovery up to 90 to 100 percent for maximum effort. A 30-year-old, for example, gets a Tanaka maximum of 187 bpm and a Zone 2 of 112 to 131 bpm. Add a resting heart rate to switch the table to the Karvonen method.

Age (years)

Resting heart rate (bpm) optional

Results are for informational purposes and do not constitute medical advice.

How it works

From age alone, each of the five zones is a fixed share of the Tanaka maximum: 50 to 60, 60 to 70, 70 to 80, 80 to 90, and 90 to 100 percent, rounded to whole beats per minute. For a 50-year-old (maximum 173 bpm) that puts Zone 1 at 87 to 104 bpm and Zone 2 at 104 to 121 bpm. Enter a resting heart rate and the same bands are applied to your heart rate reserve instead. All arithmetic runs locally in your browser.

Processing runs in your browser

All calculations happen locally using pure JavaScript. Our servers are not involved at any point.

Technical specification

The Tanaka formula (208 − 0.7 × age) was derived from a meta-analysis of 351 studies involving 18,712 subjects by Tanaka et al. and published in the Journal of the American College of Cardiology 37:1 (2001). It corrects the classic 220 − age formula, which overestimates maximum heart rate in younger adults and underestimates it in older adults; the two agree at age 40. Both formulas have a standard deviation of ±10–12 bpm. The Karvonen method uses heart rate reserve (HRR = Max HR − Resting HR) to scale zones relative to individual fitness.

Max HR formula: Tanaka: 208 − 0.7 × age (JACC 37:1, 2001)
Personalised zones: Karvonen method using heart rate reserve
Accuracy: ±10–12 bpm (population average)
Browser API: Pure JavaScript arithmetic. No library

Related operations

For estimating daily energy expenditure for training, try the calorie calculator. To capture a baseline weight category, use the BMI calculator. For tracking strength gains alongside cardio zones, see the one-rep max calculator.

Frequently asked questions

What are my heart rate zones at age 40?: At 40 the Tanaka formula gives a maximum of 180 bpm, so the zones are 90 to 108 bpm (Zone 1), 108 to 126 (Zone 2), 126 to 144 (Zone 3), 144 to 162 (Zone 4), and 162 to 180 (Zone 5). Results are estimates for informational purposes only.
Which zone burns the most fat?: The share of energy from fat is highest at easy efforts in Zones 1 and 2, and fat burned per minute usually peaks near the top of Zone 2 or the bottom of Zone 3. Zones 3 and 4 burn more total calories per minute, and for weight loss total energy use matters more than the fuel mix.
How much time should I spend in each zone?: Most endurance coaches recommend the 80/20 rule: 80% of training in Zone 1–2 (low intensity) and 20% in Zone 3–5 (higher intensity). This approach builds aerobic base while avoiding overtraining.
Does the calculator work offline?: Once the page has loaded, yes. The formula runs in the open tab, so it keeps working if your connection drops. Reloading or opening another page needs a connection again.

Last reviewed September 30, 2026

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