What is resting heart rate?
Beats per minute after sitting quietly—often measured in the morning before coffee.
Target Heart Rate Calculator
Get five training zones from recovery through max effort. Add resting heart rate for Karvonen-based zones.
Age and optional resting HR
Max HR defaults to 220 − age. Resting HR unlocks the Karvonen method.
About this calculator
How to use Target Heart Rate Calculator, plus the formulas and logic behind the results.
Tool description
Heart-rate zones help structure cardio. Karvonen uses heart-rate reserve (max − resting) for a more personalized range when resting HR is known.
How to use
- Enter your age.
- Optionally add resting HR from a quiet morning reading.
- Calculate to see five zone ranges in bpm.
- Pick a zone that matches your session goal.
Formulas & reference
Max HR ≈ 220 − ageKarvonen: target = (max − rest) × intensity + restZones: 50–60%, 60–70%, 70–80%, 80–90%, 90–100%
Zone purposes (typical)
- 50–60%: recovery / warm-up
- 60–70%: fat burn / easy aerobic
- 70–80%: aerobic base
- 80–90%: threshold / hard intervals
- 90–100%: short max efforts
Calculation logic
If resting HR is valid, each zone uses Karvonen with the listed intensity bounds. Otherwise zones are simple percentages of estimated max HR.
220 − age is an estimate. Medications, fitness, and genetics can shift your true max HR.
Target Heart Rate Calculator FAQ
Common questions about this calculator and how to use the results.
Should I use a chest strap?
Chest straps are more accurate than wrist wearables for interval work.
Can zones change as I get fitter?
Resting HR often drops with conditioning, which shifts Karvonen ranges.
Is the fat-burn zone best for fat loss?
Total calorie balance over weeks matters more than training in one zone.
What if I take beta blockers?
Ask your doctor—meds can blunt heart-rate response.
How long should I stay in each zone?
Depends on goal: easy zones for long duration, high zones for brief intervals.