Target Heart Rate Calculator
Optimize your workout using the Karvonen Formula.
*Calculated using the Karvonen Formula: Target HR = ((Max HR – Resting HR) × Intensity) + Resting HR.
How to Calculate Heart Rate for Exercise: A Complete Guide
Understanding your heart rate is the most effective way to track exercise intensity and ensure you are meeting your fitness goals. Whether you want to burn fat, improve cardiovascular endurance, or increase your athletic speed, knowing your target zones is essential.
The Karvonen Formula vs. The Simple Formula
Most basic calculators simply use the "220 minus age" rule. While easy, it often misses the mark because it doesn't account for your individual fitness level. The Karvonen Formula, which our calculator uses above, is considered far more accurate by sports scientists because it incorporates your Resting Heart Rate (RHR).
By including your RHR, the formula calculates your "Heart Rate Reserve," which represents the actual range your heart has available for physical activity.
Step-by-Step Calculation Example
Let's say you are 40 years old with a resting heart rate of 70 BPM, and you want to exercise at 70% intensity.
- Max Heart Rate (MHR): 220 – 40 = 180 BPM
- Heart Rate Reserve (HRR): 180 – 70 = 110 BPM
- Intensity Calculation: 110 x 0.70 = 77 BPM
- Final Target: 77 + 70 = 147 BPM
In this example, your target heart rate for a 70% intensity workout is 147 Beats Per Minute.
Exercise Intensity Zones
| Zone | Intensity | Benefits |
|---|---|---|
| Light | 50% – 60% | Warm-up, recovery, and basic health maintenance. |
| Weight Control | 60% – 70% | Effective for fat burning and improving metabolism. |
| Aerobic | 70% – 80% | Improves cardiovascular strength and lung capacity. |
| Anaerobic | 80% – 90% | Increases lactic acid tolerance and high-speed endurance. |
Why Monitor Your Heart Rate?
- Prevent Over-training: If your heart rate is consistently higher than expected for a specific intensity, you may be fatigued or dehydrated.
- Optimize Fat Loss: Staying within the 60-70% zone ensures your body uses fat as its primary fuel source.
- Track Fitness Progress: As you get fitter, your resting heart rate typically drops, and your heart becomes more efficient at the same workload.
How to Measure Your Resting Heart Rate
For the most accurate calculation, measure your resting heart rate first thing in the morning before getting out of bed. Place two fingers on your radial artery (wrist) or carotid artery (neck) and count the beats for 60 seconds. Repeat this for three mornings and take the average.