Heart Rate Zones Calculator
Fill in the values and the answer updates as you type.
How the Heart Rate Zones Calculator works
Max heart rate is estimated as 220 − age. The Karvonen method adds a percentage of your heart rate reserve (max − resting) to your resting rate. The 220 − age formula can be off by 10 bpm or more, so a measured max from a hard test is better. Example: with the default values, max heart rate is 185 bpm and Zone 2 runs 135–148 bpm.
Inputs and results
The Heart Rate Zones Calculator takes 2 inputs and gives 6 results.
What you enter
- Age (years) — starts at 35.
- Resting heart rate (bpm) — starts at 60.
What you get
- Estimated max heart rate (bpm)
- Zone 1: very light (50–60%)
- Zone 2: aerobic base (60–70%)
- Zone 3: tempo (70–80%)
- Zone 4: threshold (80–90%)
- Zone 5: maximum (90–100%)
Example: Heart Rate Zones Calculator with the starting values
With age 35 years and resting heart rate 60 bpm, the calculator returns:
| Estimated max heart rate (bpm) | 185 |
|---|---|
| Zone 1: very light (50–60%) | 123–135 bpm |
| Zone 2: aerobic base (60–70%) | 135–148 bpm |
| Zone 3: tempo (70–80%) | 148–160 bpm |
| Zone 4: threshold (80–90%) | 160–173 bpm |
| Zone 5: maximum (90–100%) | 173–185 bpm |
Change any value above and the results update straight away.
Heart Rate Zones Calculator FAQ
How do I use the Heart Rate Zones Calculator?
Enter age and resting heart rate in the fields, then read estimated max heart rate (bpm), zone 1: very light (50–60%), zone 2: aerobic base (60–70%) and zone 3: tempo (70–80%) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Heart Rate Zones Calculator calculate?
Training heart rate zones using the Karvonen method. It returns estimated max heart rate (bpm), zone 1: very light (50–60%), zone 2: aerobic base (60–70%) and zone 3: tempo (70–80%) from the 2 values you provide.
What values does the Heart Rate Zones Calculator start with?
It opens with age 35 years and resting heart rate 60 bpm so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Heart Rate Zones Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Heart Rate Zones Calculator for medical or health decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm medical or health decisions with a qualified professional. See the Disclaimer for more.