Target Heart Rate Calculator
Find your target heart rate for any exercise goal using both the simple percentage method and the more accurate Karvonen formula. Includes fat-burning, cardio, threshold, and peak zones with practical guidance.
bpm
Enter your values above to see the results.
Tips & Notes
- ✓The Karvonen formula produces target zones that are 10–20 bpm higher than the simple method for fit people with low resting HR — use Karvonen if your resting HR is below 65 bpm.
- ✓Measure resting HR correctly: take it lying down, first thing in the morning, before checking your phone or getting up. Even sitting up raises HR by 5–10 bpm.
- ✓On high-stress days, hot weather, or after poor sleep, heart rate will be elevated 5–10 bpm at any given effort. Use the talk test as a backup zone check on these days.
- ✓For cardiac patients or those on beta-blockers, age-based maximum HR formulas are unreliable — HR zones should be determined by a supervised exercise stress test with physician guidance.
- ✓Your resting heart rate decreasing over months of aerobic training is one of the clearest signs of cardiovascular adaptation — it shifts all Karvonen zones upward as HRR increases.
Common Mistakes
- ✗Using only the simple percentage method when resting heart rate is known — the Karvonen formula accounts for individual fitness level and produces more accurate training zones, especially for conditioned athletes.
- ✗Measuring resting HR at any random time during the day instead of immediately upon waking — mid-day resting HR can be 10–20 bpm higher than true resting HR due to activity, caffeine, and postural effects.
- ✗Training in the "fat burning zone" exclusively for weight loss — higher intensity zones burn more total calories per minute, which is more relevant to fat loss than maximizing the fat-burning percentage of calories burned.
- ✗Ignoring heart rate drift during long sessions — heart rate naturally rises 5–10 bpm over a 60–90 minute steady-pace effort at constant intensity due to progressive dehydration and cardiovascular drift. This is normal, not a sign of working harder.
- ✗Expecting maximum HR formula estimates to be exact for people over 50 — individual variation in MHR is widest in older adults, where formula accuracy is lowest. A supervised test or field test gives better zones.
Target Heart Rate Calculator Overview
Target heart rate zones define the specific physiological effect of each workout. Training above your zone produces excess fatigue without proportional benefit; training below leaves adaptation potential untapped.
Maximum heart rate and target zone formulas:
Simple Method (% of Maximum Heart Rate): Maximum HR = 220 − age Target HR = Maximum HR × % intensity Karvonen Method (Heart Rate Reserve — more accurate): Heart Rate Reserve (HRR) = Max HR − Resting HR Target HR = (HRR × % intensity) + Resting HR
EX: Person age 42, resting HR 62 bpm Max HR = 220 − 42 = 178 bpm HRR = 178 − 62 = 116 bpm Cardio Zone (70–80%) — Simple: 178 × 0.70 = 125 bpm to 178 × 0.80 = 142 bpm Cardio Zone (70–80%) — Karvonen: (116 × 0.70) + 62 = 143 bpm to (116 × 0.80) + 62 = 155 bpm Gap: up to 18 bpm — a significant training intensity difference. Karvonen is always higher for people with resting HR below ~75 bpm — it rewards cardiovascular fitness.
Karvonen formula — personalized zone calculation:
Target zones by goal: Fat oxidation (fat burning zone): 60–70% — higher fat burn per calorie, lower total calorie burn per minute Aerobic conditioning: 70–80% — cardiovascular fitness, sustained effort, most common training zone Threshold training: 80–90% — lactate threshold development, race-pace simulation, tempo work Peak/VO2 max: 90–100% — brief, high-intensity intervals only, maximal aerobic capacity
EX: Goal: 5K race improvement. Same person (Max HR 178, RHR 62, HRR 116). Easy runs (aerobic base): 60–70% Karvonen = 131–143 bpm — conversational effort Tempo runs (threshold): 80–90% Karvonen = 155–166 bpm — "comfortably hard," can speak in fragments Race pace: approximately 85–88% Karvonen = ~161–164 bpm Intervals (5K pace): 90–95% Karvonen = 166–172 bpm — 400m to 1,600m repeats
Target heart rate zones by training goal:
| Zone name | % Max HR (simple) | % HRR (Karvonen) | Feel / talk test | Primary benefit |
|---|---|---|---|---|
| Active recovery | 50–60% | 50–60% | Easy, full sentences | Recovery, blood flow |
| Fat burning | 60–70% | 60–70% | Comfortable, conversational | Aerobic base, fat oxidation |
| Aerobic cardio | 70–80% | 70–80% | Moderate, short sentences | Cardiovascular fitness |
| Threshold | 80–90% | 80–90% | Hard, 2–3 word answers | Lactate threshold, speed |
| Maximum effort | 90–100% | 90–100% | Very hard, cannot speak | VO2 max, sprint power |
Age-based max HR formula comparison:
| Heart rate monitor type | Accuracy at steady pace | Accuracy during intervals | Best use case |
|---|---|---|---|
| Chest strap (ECG-based) | ±1–3 bpm | ±2–4 bpm | All training, race monitoring |
| Wrist optical (Garmin, Apple) | ±5–8 bpm | ±10–20 bpm | General fitness tracking |
| Upper arm optical (Polar Verity) | ±3–5 bpm | ±5–10 bpm | Better than wrist for intervals |
| Earbud optical | ±5–10 bpm | ±15–25 bpm | Casual use only |
The talk test is a surprisingly reliable field method for estimating training zones without a monitor. At the fat-burning zone (Zone 2), you can speak in full, comfortable sentences. At the aerobic conditioning zone, you can speak but not easily maintain a conversation. At threshold, you can say 2–3 words between breaths. At maximum effort, speech is impossible. Experienced athletes use perceived exertion alongside heart rate to calibrate zones — on hot days or after poor sleep, heart rate may be elevated 5–10 bpm above normal, and the talk test provides a useful cross-check.
Frequently Asked Questions
Any exercise that creates a calorie deficit contributes to fat loss, and heart rate zones determine training efficiency rather than weight loss directly. The "fat burning zone" (60–70% of HRR) burns a higher proportion of fat calories but fewer total calories per minute than higher zones. For weight loss, total calorie expenditure matters more than the fat-burning percentage. Practically, training at 70–80% of HRR (aerobic zone) burns more total calories, improves cardiovascular fitness simultaneously, and is sustainable for 30–60 minute sessions — making it effective for most weight loss goals. The best zone for fat loss is whichever zone you can sustain consistently.
No — it is a population average with significant individual variation. The formula has a standard deviation of approximately 10–12 bpm, meaning about one-third of people have a true maximum HR more than 10 bpm away from the formula estimate. The formula tends to overestimate MHR for older athletes who are highly trained, and underestimate for sedentary older adults. The Tanaka formula (208 − 0.7 × age) is more accurate for adults over 40. For truly accurate heart rate zones, performing a supervised maximum effort test after a proper warm-up gives the best individual MHR estimate.
Cardiovascular drift is the normal rise in heart rate during prolonged exercise at constant intensity — typically 5–10 bpm over 60–90 minutes. It occurs because dehydration reduces plasma blood volume, requiring the heart to beat faster to maintain cardiac output. At constant pace, heart rate gradually climbs even without any increase in effort. Staying well hydrated during long sessions reduces drift significantly. Other causes of persistent elevated HR: heat and humidity (more blood redirected to skin for cooling), emotional stress before or during exercise, insufficient warm-up, or cumulative fatigue from a heavy training week.
Yes — Rate of Perceived Exertion (RPE) is a validated alternative to heart rate monitoring for zone estimation. The Borg scale (6–20) or modified RPE (0–10) correlates well with heart rate zones: RPE 11–12 corresponds to fat-burning zone (60–70%), RPE 13–14 to aerobic zone (70–80%), RPE 15–16 to threshold (80–90%). The talk test provides a simpler version: comfortable conversation = Zone 2, short sentences = Zone 3, 2–3 words = Zone 4, cannot speak = Zone 5. Experienced athletes often prefer RPE because it automatically adjusts for environmental factors that elevate heart rate independently of exercise intensity.
Consistently training above prescribed zones — particularly spending most time in Zone 3–4 when the plan calls for Zone 2 — produces cumulative fatigue faster than aerobic adaptation develops. This pattern (common in recreational athletes who feel that harder means better) leads to plateaued performance, increased injury risk, reduced motivation, and in some cases, overreaching syndrome with symptoms including elevated resting HR, sleep disruption, mood changes, and declining performance despite training. The paradox is that slowing down easy sessions to truly stay in Zone 2 often produces faster long-term improvement than grinding through Zone 3 every day.
Maximum heart rate naturally decreases with age at approximately 1 bpm per year, which is why the 220 minus age formula uses age as its only input. This means all five training zones shift downward in absolute bpm terms as you age. However, the percentage-based thresholds remain the same — a 60-year-old and a 30-year-old both train Zone 2 at 60–70% of their respective maximum HR. Resting heart rate does not necessarily increase with age in fit individuals — trained older adults can maintain resting HR in the 50s indefinitely with consistent aerobic training, which keeps HRR (and therefore Karvonen zones) relatively high despite aging-related MHR decline.