Loading...
Find your 5 heart rate training zones using age or resting HR. Supports Karvonen method.
Heart rate zones are intensity ranges expressed as percentages of your maximum heart rate, used to target specific training adaptations such as fat burning, aerobic endurance, or anaerobic power.
50–60% max HR · Active recovery, warm-up/cool-down
60–70% max HR · Fat oxidation, base endurance
70–80% max HR · Cardiovascular fitness, tempo runs
80–90% max HR · Speed, lactate threshold
90–100% max HR · Max effort, sprints
Formula
Karvonen: THR = (MHR − RHR) × %intensity + RHRTHR = Target Heart Rate (bpm)
MHR = Maximum Heart Rate — estimated as 220 − age
RHR = Resting Heart Rate (bpm)
%intensity = Zone intensity as a decimal (e.g. 0.60 for Zone 2)
Worked Example
Example: 30-year-old, resting HR 60 bpm — Zone 2 (60–70%)
Did you know? NASA uses structured heart rate zone training in astronaut fitness programs to maintain cardiovascular health during long-duration spaceflight missions.
Sources
| Zone | % Max HR | Purpose |
|---|---|---|
| Zone 1 – Recovery | 50–60% | Active recovery, warm-up/cool-down |
| Zone 2 – Fat Burn | 60–70% | Fat oxidation, base endurance |
| Zone 3 – Aerobic | 70–80% | Cardiovascular fitness, tempo runs |
| Zone 4 – Anaerobic | 80–90% | Speed, lactate threshold |
| Zone 5 – Maximum | 90–100% | Max effort, sprints |
Formula
MHR = 220 − age | Zone % = MHR × zone_low% to MHR × zone_high%MHR = Maximum Heart Rate — estimated upper limit of cardiovascular capacity
Zone 1 = 50–60% MHR — active recovery, very light effort
Zone 2 = 60–70% MHR — aerobic base, fat-burning zone
Zone 4–5 = 80–100% MHR — anaerobic threshold and VO₂ max training
Worked Example
Heart rate zones for a 35-year-old
Did you know? The '220 minus age' formula for max heart rate was popularized in 1970 but was never validated in a research study — it was derived informally from data observations. More accurate equations exist (e.g., Tanaka: MHR = 208 − 0.7×age), though individual variation remains high (±10–12 bpm).
Sources
Calculate BMR using 3 validated formulas. See daily calorie needs by activity level.
Estimate BAC using the Widmark formula. Enter drinks, weight, and hours to gauge impairment.
Calculate BMI and see your weight category. Includes healthy weight range for your height.
Calculate body fat percentage using the US Navy method with simple body measurements.
Calculate daily calorie needs with BMR and TDEE. Get targets for weight loss, maintenance, or gain.
Calculate gestational age from your LMP. See due date, trimester, and milestones.