Hjertefrekvenszonkalkulator
Calculate your target heart rate zones for training. Based on your age and resting heart rate using the Karvonen formula.
Slik bruker du denne kalkulatoren
- Skriv inn Age
- Skriv inn Resting Heart Rate (bpm)
- Klikk på Beregn-knappen
- Les resultatet som vises under kalkulatoren
Understanding Maximum Heart Rate and Why It Matters
Your maximum heart rate (MHR) is the highest number of times your heart can beat per minute during all-out effort. It is primarily determined by age and genetics — training does not raise it significantly. The classic formula MHR = 220 − age is simple and widely used, but research shows it can be off by 10–20 bpm for many individuals.
More accurate alternatives include the Tanaka formula: MHR = 208 − (0.7 × age), which performs better across age groups, and the Karvonen (Heart Rate Reserve) method, which factors in your resting heart rate to set truly personalized training zones.
The Karvonen formula: Target HR = ((MHR − RHR) × intensity%) + RHR, where RHR is resting heart rate. For a 35-year-old with RHR of 55 bpm wanting to train at 70% effort: ((185 − 55) × 0.70) + 55 = 91 + 55 = 146 bpm. This is meaningfully different from the simple percentage method (185 × 0.70 = 130 bpm).
The Five Heart Rate Training Zones Explained
Heart rate training zones give structure to your workouts, ensuring you spend time at the right intensity for your goals. Each zone produces distinct physiological adaptations:
| Zone | % of MHR | Feel | Primary Benefit | Example for MHR 185 |
|---|---|---|---|---|
| Zone 1 – Recovery | 50–60% | Very easy, can sing | Active recovery, fat metabolism | 93–111 bpm |
| Zone 2 – Aerobic Base | 60–70% | Easy, full sentences | Aerobic endurance, mitochondria density | 111–130 bpm |
| Zone 3 – Tempo | 70–80% | Moderate, short phrases | Aerobic capacity, lactate threshold | 130–148 bpm |
| Zone 4 – Threshold | 80–90% | Hard, single words | Speed endurance, VO2max | 148–167 bpm |
| Zone 5 – VO2max | 90–100% | Maximum, cannot speak | Peak performance, anaerobic power | 167–185 bpm |
Elite endurance coaches follow the 80/20 rule: roughly 80% of training in Zones 1–2 and 20% in Zones 4–5. This prevents overtraining while still driving adaptation. Zone 3 is the "junk miles" zone — uncomfortable enough to tire you out, but not intense enough to deliver the benefits of Zone 4 work.
Resting Heart Rate: Your Fitness Barometer
Resting heart rate (RHR) is one of the simplest and most reliable indicators of cardiovascular fitness. Measure it first thing in the morning before getting out of bed — lie still, count beats for 60 seconds, or count for 15 seconds and multiply by 4.
| Category | Men (bpm) | Women (bpm) |
|---|---|---|
| Athlete | 40–50 | 40–52 |
| Excellent | 51–58 | 53–60 |
| Good | 59–65 | 61–68 |
| Average | 66–73 | 69–76 |
| Below Average | 74–81 | 77–84 |
| Poor | 82+ | 85+ |
A sudden increase in resting heart rate of 5–7 bpm above your normal baseline is a reliable early warning sign of overtraining, illness, or poor recovery. Track your RHR daily — it costs nothing and tells you a great deal about your body's state.
Heart Rate Zones by Age: Quick Reference
The table below shows approximate Zone 2 (aerobic base) and Zone 4 (threshold) heart rate ranges by age, calculated using the 220 − age formula. Use these as starting points and adjust based on feel and real-world performance testing.
| Age | Est. MHR | Zone 2 (60–70%) | Zone 4 (80–90%) |
|---|---|---|---|
| 20 | 200 | 120–140 | 160–180 |
| 25 | 195 | 117–137 | 156–176 |
| 30 | 190 | 114–133 | 152–171 |
| 35 | 185 | 111–130 | 148–167 |
| 40 | 180 | 108–126 | 144–162 |
| 45 | 175 | 105–123 | 140–158 |
| 50 | 170 | 102–119 | 136–153 |
| 55 | 165 | 99–116 | 132–149 |
| 60 | 160 | 96–112 | 128–144 |
| 65 | 155 | 93–109 | 124–140 |
These are estimates. If you want precise zones, conduct a lactate threshold test with a sports physiologist or use a structured 30-minute field test: warm up, then run at the fastest pace you can sustain for 30 minutes. Average heart rate of the final 20 minutes approximates your lactate threshold heart rate.
Heart Rate Monitoring Technology
Modern athletes have several options for heart rate monitoring, each with different accuracy profiles:
- Chest strap (ECG-based): Gold standard for accuracy (±1 bpm). Detects the electrical signal of each heartbeat directly. Best for high-intensity training, interval work, and when precision matters most. Brands: Garmin HRM-Pro, Polar H10, Wahoo TICKR.
- Wrist-based optical (PPG): Measures blood flow changes through the skin using green LEDs. Convenient but less accurate during rapidly changing intensity or wrist movement. Accuracy improves during steady-state efforts. Built into most smartwatches.
- Arm-based optical: Better than wrist-based for cyclists and during activities with significant wrist movement. Brands: Polar OH1, Garmin HRM-Fit.
- Earbuds with PPG: Emerging technology with promising accuracy for steady-state exercise.
For race-day pacing and structured interval sessions, invest in a chest strap. For general fitness tracking and daily steps, a wrist sensor is perfectly adequate.
Practical Heart Rate Strategies for Runners
Heart rate-based training is particularly powerful for runners. Here are evidence-based strategies:
Easy run pacing: Most recreational runners run their easy days too fast. If you can't hold a full conversation, you're probably in Zone 3 when you should be in Zone 2. Slow down — it takes discipline, but it builds your aerobic base faster long-term.
Cardiac drift: On long runs, especially in heat, heart rate climbs over time even at constant pace. This is normal and caused by dehydration and thermoregulation demands. On hot days, reduce pace to keep heart rate stable rather than chasing a pace target.
New runner note: When beginning a run program, your heart rate zones will seem frustratingly slow. Walking breaks during Zone 2 runs are completely normal. Over 8–12 weeks, your pace at Zone 2 will increase significantly as your aerobic base develops — this is exactly the adaptation you're training for.
Race day: In a 5K, expect to spend the majority of time in Zones 4–5. In a marathon, your target is the upper end of Zone 3 to low Zone 4 — any higher and you risk hitting the wall as glycogen depletes prematurely.
"Regelmessig fysisk aktivitet kan senke blodtrykket, forbedre kolesterolnivåer og redusere risikoen for hjertesykdom. Voksne bør få minst 150 minutter med moderat-intensiv aerob aktivitet eller 75 minutter med kraftig aktivitet per uke."
💡 Visste du?
- Your heart beats approximately 100,000 times per day — around 2.5 billion times over an average lifetime.
- The classic formula "Max HR = 220 − age" was popularized in 1971 and has a margin of error of ±10–12 bpm; newer formulas like 207 − (0.7 × age) are more accurate.
- Trained endurance athletes can have resting heart rates as low as 28–40 bpm; the average untrained adult is 60–100 bpm.
Sist oppdatert: March 2026
Frequently Asked Questions
How do I find my resting heart rate?
Measure your pulse first thing in the morning before getting out of bed. Lie still and count beats for 60 seconds (or count for 15 seconds × 4). For accuracy, measure on 3 consecutive mornings and take the average. Normal resting heart rate is 60–100 bpm; fit athletes are often 40–55 bpm.
Is the 220-minus-age formula accurate?
It provides a reasonable estimate for most people but can be off by 10–20 bpm. The Tanaka formula (208 − 0.7 × age) is slightly more accurate. For precision, conduct a maximal exercise test under medical supervision or use the Karvonen method with your measured resting heart rate.
What heart rate zone burns the most fat?
Zone 2 (60–70% MHR) uses the highest percentage of fat as fuel — roughly 85% fat vs. 15% carbohydrates. However, higher-intensity zones burn more total calories per minute. For overall fat loss, total calorie balance over the day matters more than which zone you train in.
Why does my heart rate stay high after stopping exercise?
Heart rate recovery (HRR) — how quickly your HR drops after exercise — is a strong fitness indicator. A healthy person's HR should drop at least 12 bpm in the first minute after stopping vigorous exercise. Poor HRR has been linked to increased cardiovascular risk. Regular aerobic training improves HRR significantly.
What is a dangerously high heart rate during exercise?
For most healthy adults, exercising up to 85–100% of MHR briefly is safe. Sustained periods above 85% MHR without prior fitness testing or physician clearance is not recommended, especially if you're over 40 or have cardiovascular risk factors. Warning signs: chest pain, severe shortness of breath, dizziness, or palpitations — stop immediately and seek medical attention.
How does caffeine affect heart rate?
Caffeine is a stimulant that can raise resting heart rate by 5–15 bpm and increase peak heart rate during exercise. This can make heart rate data unreliable on days you've consumed caffeine. If you use heart rate zones for training, try to be consistent about caffeine timing.
Why is my heart rate higher on hot days?
In heat, your body diverts more blood to the skin for cooling (thermoregulation), leaving less available for working muscles. Your heart beats faster to compensate. Add 10–15 bpm to your perceived exertion in hot, humid conditions, or use perceived effort rather than heart rate as your guide.
What is heart rate variability (HRV) and should I track it?
HRV measures the variation in time between successive heartbeats. Higher HRV generally indicates good recovery and autonomic nervous system balance. Many elite athletes track morning HRV to decide training intensity. Apps like HRV4Training or Elite HRV provide guidance. A declining trend in HRV over several days suggests accumulated fatigue.