How to find your max heart rate.
Every heart-rate zone — including the 85% threshold that defines a VO₂max interval — is a percentage of your maximum heart rate. Here are four ways to find it, from quick estimate to gold standard.
The formulas (quick estimates)
- 220 − age. The famous one. Simple, but rough — it overestimates in the young and underestimates in older adults.
- 208 − (0.7 × age) — Tanaka.Derived from a large meta-analysis; more accurate across ages. The better default if you're going to use a formula.
| Age | 220 − age | Tanaka (208 − 0.7·age) |
|---|---|---|
| 20 | 200 bpm | 194 bpm |
| 30 | 190 bpm | 187 bpm |
| 40 | 180 bpm | 180 bpm |
| 50 | 170 bpm | 173 bpm |
| 60 | 160 bpm | 166 bpm |
| 70 | 150 bpm | 159 bpm |
Estimates only — true max heart rate varies by 10–20 bpm between individuals of the same age.
The field test (better)
A hard effort beats any formula. After a long warm-up, do several minutes near all-out — for example, two to three hard 3-minute hill efforts back to back — and note the highest heart rate you reach. That figure is close to your true max. Only attempt a maximal test if you're healthy and cleared for intense exercise; stop if anything feels wrong.
The lab test (gold standard)
A graded exercise test (the same CPET used to measure VO₂max) measures your true max heart rate directly under supervision. It's the most accurate option and the one to use if you have any cardiovascular risk factors.
Frequently asked questions
- What is the formula for max heart rate?
The classic estimate is 220 minus your age. A more accurate population formula is Tanaka's: 208 − (0.7 × age). Both are estimates — an individual's true max can be 10–20 bpm higher or lower.
- Is 220 minus age accurate?
It's a rough guide, not a precise figure. It was never derived from rigorous research and tends to overestimate max heart rate in younger adults and underestimate it in older ones. Tanaka's formula is more accurate on average, and a field or lab test beats any formula.
- How do I test my actual max heart rate?
Do a hard, supervised effort: after a thorough warm-up, several minutes near all-out (for example, repeated hard hill efforts) until you can't push your heart rate any higher. The highest value you see is close to your max. Only do this if you're healthy and cleared for maximal exercise.
- Why does max heart rate matter for interval training?
Heart-rate zones are defined as percentages of your max, so the Norwegian 4×4's 85% threshold is only as good as your max-HR number. Get the max wrong and every zone shifts with it.
Train at VO₂max.
Set your max once, and Stellar Intervals runs the 4×4 against your real 85% threshold every session.