Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Calculate your 5 training heart rate zones using the Karvonen formula.
This tool calculates 5 training heart rate zones using the Karvonen formula (heart-rate reserve method) -- the standard exercise-physiology approach, which accounts for your resting heart rate rather than just age, giving more individualized zones than a simple percentage-of-max method.
Enter your age and resting heart rate (measured first thing in the morning, before getting up, for best accuracy). Your 5 zones appear instantly.
Max HR = 220 - Age
Heart Rate Reserve (HRR) = Max HR - Resting HR
Zone = Resting HR + (HRR × Intensity%)
Zones: 1 Very Light (50-60%), 2 Light (60-70%), 3 Moderate (70-80%), 4 Hard (80-90%), 5 Maximum (90-100%).
Use these zones to structure training -- easy runs in Zone 2, tempo work in Zone 3-4, intervals in Zone 5. For a simpler percentage-of-max approach without resting HR, see the Target Heart Rate Calculator.
Take a 30 year old with a resting heart rate of 60 bpm, which matches the tool's starting inputs. Max heart rate is 220 - 30 = 190. Heart rate reserve is 190 - 60 = 130. Zone 1 runs from 60 + 130 x 0.5 = 125 to 60 + 130 x 0.6 = 138. Zone 2 runs 138 to 151, Zone 3 runs 151 to 164, Zone 4 runs 164 to 177, and Zone 5 runs 177 to 190. Each boundary is rounded to the nearest whole beat. Notice that the top of one zone equals the bottom of the next, so a reading exactly on the border belongs to whichever zone you consider it, and you should not worry about being one beat off.
Zone bpm = resting HR + (max HR - resting HR) x intensity. Example Zone 3 low: 60 + 130 x 0.70 = 151.
To see why the Karvonen method matters, change only the resting heart rate. With a resting rate of 50 instead of 60, the reserve becomes 140 and Zone 2 shifts to 120 + ... more precisely 50 + 140 x 0.6 = 134 to 50 + 140 x 0.7 = 148. The same person with a higher resting rate of 70 has a reserve of 120 and a Zone 2 of 142 to 154. The zones move, and that is the point: two people of the same age get different targets because their resting rates differ.
Combine the numbers with how you actually feel. If a heart rate monitor says you are in Zone 2 but breathing is labored, believe your body and slow down.
If you have a heart condition, chest pain, dizziness, or take heart-related medication, get guidance from a doctor before using zone-based training. This page is educational and is not medical advice.
It accounts for individual fitness level -- someone with a lower resting HR (often fitter) gets a wider, more personalized training range than a simple age-based percentage method would give.
Take it first thing in the morning, before getting out of bed, for several days and average the results for the most reliable reading.
No -- it's a widely used population-average estimate with meaningful individual variation; a lab-measured max HR test would be more precise if available.
Each zone ends at the same percentage where the next begins, so the upper edge of one zone matches the lower edge of the next.
A lower resting rate increases your reserve and widens the zones. Enter your true measured value, not an assumption.
It is 220 minus your age, a rough population estimate. If you have measured your real maximum, the zones here will not use it, so treat them as approximate.
The tool does not calculate that. Total energy use and consistency matter more for weight goals than staying in one zone.
Reference: Centers for Disease Control and Prevention