Target Heart Rate Calculator
For a 35-year-old training at 70% of maximum, the target is about 129 bpm using the simple method. If you know your resting heart rate, the Karvonen formula gives a more personalised figure by working from your heart rate reserve rather than a flat percentage of maximum. Both are estimates.
What is Target Heart Rate Calculator?
Target heart rate is the range you aim to hold during a workout to produce a specific training effect — easy aerobic work, or harder intervals.
The simple method takes a flat percentage of estimated maximum. The Karvonen method uses your heart rate reserve (maximum minus resting) instead, which usually gives a slightly higher and more accurate target, especially for fitter people with low resting heart rates.
How to use this calculator
- Enter your age.
- Enter your resting heart rate if you know it — measured first thing in the morning, sitting quietly.
- Choose the intensity you want to train at.
- Use the Karvonen figure if you entered a resting rate; otherwise use the simple one.
How target heart rate is calculated▾
The simple method multiplies estimated maximum heart rate by your chosen intensity. The Karvonen method treats resting heart rate as the floor and adds the same percentage of the remaining range, which better reflects how much cardiac capacity you actually have available.
Simple: target = max HR × intensity
Karvonen: target = resting HR + (max HR − resting HR) × intensity
max HR estimated as 208 − 0.7 × ageSource: Karvonen & Vuorimaa heart rate reserve method.
Frequently asked questions
Should I use the simple or Karvonen method?▾
Karvonen if you know your resting heart rate, because it accounts for fitness level. The simple method treats everyone with the same maximum identically.
How do I measure resting heart rate?▾
Right after waking, before getting up or having caffeine. Count your pulse for 60 seconds, or use a wearable's overnight average. Averaging several mornings gives a stable number.
What zone should I train in for fat loss?▾
The 'fat-burning zone' burns a higher proportion of fat but fewer total calories. Total energy expenditure matters more for fat loss, so higher intensities usually burn more overall.
Do medications affect this?▾
Yes, significantly. Beta blockers and some other drugs cap heart rate, making percentage-based zones misleading. If you take heart medication, ask your doctor for a personalised range.
Related calculators
References & method
- Karvonen & Vuorimaa heart rate reserve method.
Every formula, its published source and its assumptions are listed on our methodology page. This page is written for information and has not been reviewed by a clinician.
Read the methodology →These figures are estimates from population formulas, not medical advice. Individual needs vary. If you are pregnant, managing a medical condition, or under 18, talk to a doctor before changing your diet.