Cardio
Karvonen target heart rate
The reserve-based method. Take the share of the reserve first, then add the resting rate back as the baseline.
The Formula
Target = Resting + (Max - Resting) x Intensity
The reserve-based method. Take the share of the reserve first, then add the resting rate back as the baseline.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| HRrest | Resting heart rate | beats per minute | Measured while still in bed, before any activity. |
| HRmax | Estimated maximum heart rate | beats per minute | Usually 220 minus age, itself an estimate. |
| I | Training intensity | dimensionless | Share of the reserve, written as a decimal such as 0.7. |
What Each Symbol Means
HRrestbeats per minute
Resting heart rate
Measured while still in bed, before any activity.
HRmaxbeats per minute
Estimated maximum heart rate
Usually 220 minus age, itself an estimate.
Idimensionless
Training intensity
Share of the reserve, written as a decimal such as 0.7.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate target heart rate page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Target Heart Rate, filed under Health. Every number the guide produces comes from substituting into this one line.