Target Heart Rate Zones for Age 25 (Resting HR 55 bpm)
Calculate training zones for a fit 25-year-old with an athletic resting heart rate of 55 bpm.
How to use this tool
- Enter age and resting heart rate in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your zone 1 low (50%) and the full breakdown beneath it.
Athletes in their mid-20s often have lower resting heart rates — calculate your personalized zones with a 55 bpm RHR.
Frequently asked questions
- What is the Karvonen formula?
- Karvonen target HR = (Max HR - Resting HR) × intensity% + Resting HR. It gives more personalised zones than simple percentage-of-max because it accounts for your cardiovascular fitness.
- Which zone is best for fat burning?
- Zone 2 (60–70% of max) is the classic fat-burning zone. Higher zones burn more total calories but use a higher proportion of carbohydrates.