For a 45-year-old, the Tanaka formula estimates a maximum heart rate of about 177 bpm. That puts your Zone 2 (easy aerobic) at roughly 106–124 bpm and your Zone 4 (threshold) at 142–159 bpm. Below you will find the full 5-zone table, a formula comparison, and a calculator that personalises the numbers if you enter your resting HR.
| Zone | Name | % HRmax | BPM (age 45) |
|---|---|---|---|
| 1 | Recovery | 50–60% | 89–106 |
| 2 | Endurance | 60–70% | 106–124 |
| 3 | Aerobic | 70–80% | 124–142 |
| 4 | Threshold | 80–90% | 142–159 |
| 5 | Maximum | 90–100% | 159–177 |
No single equation is authoritative. The spread below shows why picking a formula matters — the difference between Fox and Nes at your age moves your Zone 2 ceiling by several beats.
| Formula | HRmax at age 45 |
|---|---|
| Fox (220 − age) | 175 |
| Tanaka (208 − 0.7 × age) | 177 |
| Gellish (207 − 0.7 × age) | 176 |
| Nes / HUNT (211 − 0.64 × age) | 182 |
| Gulati (206 − 0.88 × age, women) | 166 |
Typical resting heart rate: 55–70 bpm.
Typical VO2max reference (good/very good): Men 36–41 ml/kg/min (good); women 30–35 ml/kg/min (good). Source: ACSM norms and HUNT Fitness Study.
Why HRmax sits where it does at 45: HRmax and stroke volume both matter now. A supervised field test corrects formula errors of up to 15 bpm — a spread that meaningfully changes every zone.
Two Zone 2 sessions of 45–60 minutes, one long Zone 2 of 75–90 minutes, one Zone 4 threshold session, and two strength sessions.
Formula spread is widest in the mid-forties, so an estimated HRmax can be off by enough to shift every zone. A measured value from a hard, well-warmed-up effort anchors the zones to you rather than to a population average. This tool provides training estimates, not medical advice — if you want individual guidance before testing hard, use a qualified health professional.
Using the Tanaka formula (208 − 0.7 × age), the estimated maximum heart rate for a 45-year-old is about 177 bpm. Population variability is roughly ±10–12 bpm, so your true HRmax could sit anywhere between 167 and 187 bpm.
Zone 2 for a 45-year-old is approximately 106–124 bpm, which corresponds to 60–70% of an estimated HRmax of 177 bpm. You should be able to hold a full conversation at this intensity.
Zone 4 (lactate threshold) for a 45-year-old is roughly 142–159 bpm — 80–90% of HRmax. At this intensity you can only speak in short phrases.
Enter your resting heart rate into the calculator to apply the Karvonen method, which anchors zones to your heart rate reserve. This is significantly more accurate than %HRmax alone, especially if you are trained or untrained.
Formula spread is widest in the mid-forties, so an estimated HRmax can be off by enough to shift every zone. A measured value from a hard, well-warmed-up effort anchors the zones to you rather than to a population average. This tool provides training estimates, not medical advice — if you want individual guidance before testing hard, use a qualified health professional.
Disclaimer: This calculator is for informational purposes only and does not provide medical advice. Always consult with a healthcare professional before starting any new exercise program.
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