Target Heart Rate Calculator
Karvonen training-zone heart rates
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Target Heart Rate Calculator
Training at the right heart rate makes cardio far more effective. This calculator uses the Karvonen formula — based on your heart-rate reserve (max minus resting heart rate) — to give the beats per minute for each training intensity from 50% to 90%, plus the classic 60–70% fat-burning zone. Because it uses your resting heart rate, it is more personalised than a simple percentage of maximum. Enter your age and resting pulse to set accurate zone targets for any workout.
Uses the Karvonen formula on heart-rate reserve: target = (max − resting) × intensity + resting, with max ≈ 220 − age. It is more individual than a plain % of max because it accounts for fitness via your resting heart rate.
How to use this target heart rate calculator
Enter your age and your resting heart rate — the pulse you have while calm and still, ideally counted first thing in the morning before you get up. Then press calculate and your target training zones appear instantly in beats per minute, from an easy 50% up to a hard 90%, with no sign-up. Read your resting pulse by feeling your wrist or neck for a full minute, or copy it from a fitness watch that tracks it overnight.
How to read and use your range
Each row is the bpm window to hold for that effort level. For easy recovery or fat-burning work, stay near the lower zones of roughly 50–70% of your reserve, where you can still talk in short sentences. For building cardio fitness, push into the harder 70–85% band during intervals or a tempo run. Check your pulse mid-workout, or wear a chest strap or watch, and ease off or speed up to keep the number inside your chosen zone.
The science behind the numbers
This tool uses the Karvonen method, built on your heart-rate reserve: target = (MHR − RHR) × intensity + RHR, where MHR is your estimated maximum, about 220 − age. Reserve is simply the gap between your maximum and resting rates, and it is the part of your range that exercise actually uses. Anchoring zones to your own RHR makes them more personal than a plain percentage of MHR, because a fitter heart beats slower at rest and gets credit for it.
Limits and practical tips
The zones are only as good as their inputs: the 220 − age rule for MHR can be off by a dozen beats for some people, and a resting pulse measured after coffee, stress or a poor night reads high. Take RHR calmly at waking, and remember that caffeine, illness and some medications shift it. Recalculate every few weeks as you get fitter and your RHR drifts down. For deeper context, pair this with CaloNote's Max Heart Rate, Heart Rate Zone and VO2 Max calculators, and log your workouts in the CaloNote app.
Frequently Asked Questions
- What is target heart rate and how is it calculated?
- Target heart rate is the beats-per-minute range that keeps you in a chosen training intensity. This tool uses the Karvonen heart-rate-reserve method, which factors in your resting heart rate and age, giving more personalised zones than a plain percentage of maximum heart rate.
- How does the Karvonen formula work?
- Karvonen subtracts your resting heart rate from your maximum (about 220 minus age) to get heart-rate reserve, multiplies that by the target intensity percentage, then adds resting heart rate back. Enter your age and resting pulse and the calculator builds each training zone for you.
- What heart rate is the fat-burning zone?
- The fat-burning zone usually sits around 60–70% of heart-rate reserve, a moderate effort where you can still hold a conversation. It's where a high share of calories comes from fat, though higher-intensity work burns more total calories per minute.