Karvonen Heart Rate Zone Calculator
Training zones using heart rate reserve.
Enter your values
Enter the age in years.
Enter the resting heart rate in bpm.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Max heart rate (est.)
- 185 bpm
- Zone 1 (50-60%)
- 124-136 bpm
- Zone 2 (60-70%)
- 136-148 bpm
- Zone 3 (70-80%)
- 148-160 bpm
- Zone 4 (80-90%)
- 160-173 bpm
- Zone 5 (90-100%)
- 173-185 bpm
Quick answer
The Karvonen method sets zones from heart rate reserve (max minus resting HR), giving more personalised zones than max-HR percentage alone.
target HR = ((max HR - resting HR) x %intensity) + resting HR
At a glance
| What it does | Training zones using heart rate reserve. |
|---|---|
| Category | Fitness |
| Inputs needed | Age, Resting heart rate |
| Main output | Max heart rate (est.) |
| Formula | target HR = ((max HR - resting HR) x %intensity) + resting HR |
| Cost | Free — no sign-up, no download |
How to use the Karvonen Heart Rate Zone Calculator
- 1Enter your age (to estimate max HR as 220 minus age) and your resting heart rate measured first thing in the morning.
- 2The Karvonen method accounts for individual fitness via resting HR, unlike simple max-HR percentage zones.
- 3220-minus-age is only an estimate — a lab or field max-HR test gives a more accurate number.
Inputs explained
- Age(years)
- Enter the age in years.
- Resting heart rate(bpm)
- Enter the resting heart rate in bpm.
Worked example
Using the values the calculator loads with:
Inputs
- Age35 years
- Resting heart rate62 bpm
Results
- Max heart rate (est.)185 bpm
- Zone 1 (50-60%)124-136 bpm
- Zone 2 (60-70%)136-148 bpm
- Zone 3 (70-80%)148-160 bpm
- Zone 4 (80-90%)160-173 bpm
- Zone 5 (90-100%)173-185 bpm
Frequently asked questions
Why use heart rate reserve instead of max HR percentage?
It accounts for individual cardiovascular fitness, since a fitter person has a lower resting HR and thus different training zones at the same relative intensity.
How do I measure resting heart rate?
Check your pulse first thing in the morning, before getting out of bed, for the most accurate baseline.
What do I need to enter into the Karvonen Heart Rate Zone Calculator?
Just 2 values: age, resting heart rate. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Karvonen Heart Rate Zone Calculator work out the answer?
The Karvonen method sets zones from heart rate reserve (max minus resting HR), giving more personalised zones than max-HR percentage alone. It applies the formula target HR = ((max HR - resting HR) x %intensity) + resting HR and shows the working so you can check each step by hand.
Is the Karvonen Heart Rate Zone Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.