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Heart Rate Zone Calculator

Enter your age (and optionally your resting heart rate) to calculate your maximum heart rate and target heart rates for 5 training zones using the Karvonen formula. Fat burn, aerobic, and anaerobic zones at a glance.

Last updated: 2026/10/16 Calculator Feedback & bug reports
Input
Please enter a value between 1 and 120
Please enter a value between 30 and 120 bpm

For accuracy, measure for one minute right after waking up. If left blank, zones are calculated as a percentage of max heart rate.

Results
Max Heart Rate (est.) --bpm
Heart Rate Reserve (HRR) --bpm
Method --
Target Heart Rate by Training Zone
Zone Type Intensity Target HR Main Effect

Max heart rate is estimated as "220 - age".

Results are approximate, based on general formulas, and are not medical advice or a diagnosis. The "220 - age" formula is an estimate with large individual variation. If you have a heart condition, take medication, or are unsure about exercising, always consult a doctor before starting.

How to Use

1

Enter your age

Enter your age and your max heart rate (220 - age) is calculated automatically.

2

Enter resting heart rate (optional)

Add your resting heart rate to get personalized targets via the Karvonen formula. Without it, the %HRmax method is used.

3

Check the zone table

Target heart rates (bpm) for each zone such as fat burn, aerobic, and anaerobic are listed.

4

Use the results

Use "Copy Results" to paste the zones into your training plan or notes.

About Heart Rate Zones

Heart rate zones divide exercise intensity into five ranges of heart rate (bpm). This tool estimates max heart rate as "220 - age" and calculates target heart rates for each zone using either the Karvonen formula (which factors in resting heart rate) or a percentage of max heart rate (%HRmax). All processing happens in your browser; no data is sent to servers.

Features

  • Karvonen FormulaEnter your resting heart rate for personalized targets based on heart rate reserve.
  • 5-Zone OverviewSee target heart rates for all five zones - fat burn, aerobic, anaerobic and more - at once.
  • Privacy ProtectedAll processing happens in your browser. Your input is never sent to servers.
  • Free, No Sign-upNo registration, no installation. Just open and use.

Use Cases

  • Finding your fat-burning zone for weight loss
  • Managing intensity for running and cycling
  • Reference for setting smartwatch heart rate zones
  • Setting target heart rates for interval training
  • Guideline for switching between aerobic and anaerobic work

FAQ

How is max heart rate calculated?
It uses the most common formula, "220 - age". For example, a 30-year-old gets 220 - 30 = 190 bpm. It is a statistical estimate with large individual variation, so use it as a guideline.
What is the Karvonen formula?
The Karvonen formula is "Target HR = (Max HR - Resting HR) x Intensity + Resting HR". Because it factors in resting heart rate (heart rate reserve), it gives targets that fit your fitness better than a simple %HRmax method.
How intense is the fat-burning zone?
The fat-burning zone is generally about 60-70% of max heart rate (or heart rate reserve), where fat is used efficiently as fuel. Note that total calorie burn rises with intensity, so choose a zone based on your goal.
Can I use it without a resting heart rate?
Yes. With age alone, the tool uses the %HRmax method (a percentage of max heart rate). Adding your resting heart rate switches to the more precise Karvonen formula.
Are the results medically accurate? Is it safe to use?
The results are approximate values from general formulas and are not medical advice or a diagnosis. Your input is processed only in your browser and never sent to servers, so your privacy is protected. If you have a heart condition, take medication, or are unsure about exercising, always consult a doctor before starting.

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Related Guides

What Are Heart Rate Zones? Max HR, the Karvonen Method, and Fat-Burning A beginner-friendly guide to heart rate zones: estimating max heart rate (220 minus age), the Karvonen method using resting heart rate, the fat-burning and aerobic zone ranges, how to gauge exercise intensity, and how to measure resting heart rate. This article is general information, not medical advice. What Is 1RM (One-Rep Max)? Formulas, %1RM Chart, and Goal-Based Loading Learn what 1RM (one-rep max) is from the ground up: estimation formulas such as Epley and Brzycki, a %1RM chart showing the relationship between reps and weight, goal-based loading for strength, hypertrophy, and endurance, and how to measure it safely.