Heart Rate Zone Calculator
Heart rate zones — what they are
Heart rate (HR) zones split your effort into ranges that target different training effects — from easier aerobic work to high-intensity intervals. Using zones helps you train smarter, recover better, and measure progress consistently.
Zones are estimates and can vary by fitness, genetics, and environment (heat, altitude, stress).
How the calculator works
- Enter your age and choose a Max HR formula (220−age or 208−0.7×age).
- Pick the method: Simple (% of Max HR) or Karvonen (uses Resting HR).
- If Karvonen is chosen, enter your Resting HR (average morning pulse, 3–5 days).
- Press Calculate in the tool to see your zone ranges.
Inputs you’ll use
- Age: used to estimate Max HR if no lab test is available.
- Max HR formula: choose 220−age or 208−0.7×age (Tanaka).
- Resting HR (optional): needed for the Karvonen method.
Tip: Measure Resting HR after waking up, sitting/lying still, for several mornings; average the readings.
Methods & formulas
Max HR (estimate)
220 − age
208 − (0.7 × age)
Both are estimates; pick the one you prefer for consistency.
Simple method
Zone range = % × Max HR
Example: Zone 2 (60–70%) = 0.60–0.70 × Max HR
Karvonen method
HRR = Max HR − Resting HR
Zone range = (HRR × %) + Resting HR
Adjusts for fitness by accounting for Resting HR.
Typical 5-zone model
Percentages refer to Max HR for the Simple method. For Karvonen, they apply to Heart Rate Reserve.
Helpful training tips
- Start easy: most base sessions in Zones 1–2 to build aerobic capacity.
- Use intervals sparingly in Zones 4–5; prioritize quality and full recovery.
- Re-check Resting HR monthly; decreases often indicate improved fitness.
- Pair HR with RPE (perceived exertion) and pace/power for context.
Common mistakes
- Using max-effort sprint spikes as “Max HR”. Use a formula or lab test instead.
- Training too hard on easy days; Zone 2 should feel conversational.
- Ignoring hydration, heat, caffeine — all can elevate HR.
Frequently asked questions
Which Max HR formula should I use?
Both 220−age and 208−0.7×age are approximations. Pick one and stay consistent for tracking. A supervised lab test is most accurate.
Why is my HR higher on some days?
Heat, dehydration, stress, lack of sleep, caffeine, and recent hard training can all raise heart rate for the same effort.
Should I always train by heart rate?
HR is a great guide, but combine it with pace/power and how you feel (RPE) for the most complete picture.
Is the Karvonen method better?
Karvonen accounts for Resting HR and may track fitness changes better for some people. Try both; use the one that matches your effort perception.
Safety & medical note
If you’re new to exercise, have a medical condition, or take heart-affecting medication, consult a healthcare professional before high-intensity training. Stop if you feel chest pain, dizziness, or unusual shortness of breath.