How to Use the Calculator
- Enter your age. The calculator estimates your max heart rate with the Tanaka formula (208 − 0.7 × age), the default in FITIV Pulse.
- Add your known max, if you have one. A peak heart rate from a hard test or race is more accurate than any formula, so it replaces the estimate.
- Change the formula or zone method, if you like. Open More options. The recommended choices match FITIV Pulse's defaults. Heart rate reserve also uses your resting heart rate, and lactate threshold uses the heart rate you can hold for about an hour of hard effort.
The Five Heart Rate Zones
With the default % of max method, the zones are:
| Zone | % of max HR | What it trains |
|---|---|---|
| Z1 Warmup | 50–59% | Warm-ups, cool-downs, and easy recovery |
| Z2 Fitness | 60–69% | Easy effort you can keep up for a long time; the bulk of most training plans |
| Z3 Endurance | 70–79% | Steady efforts that balance intensity and endurance |
| Z4 Hardcore | 80–89% | The highest heart rate you can usually hold for long stretches |
| Z5 Red Line | 90–100% | Short, very hard intervals you can't sustain for long |
Each zone starts at its percentage, rounded up to the next whole beat, and runs up to one beat below the next zone. For a deeper look at what each zone does to your body, and how to split your week between them, see Heart Rate Zones Explained.
Max Heart Rate Formulas
Every zone depends on your max heart rate, so the estimate matters. The calculator offers the same three formulas as FITIV Pulse:
- Tanaka, Monahan & Seals: 208 − 0.7 × age. The best-supported of the three, and the default in FITIV Pulse. It reads higher than 220 − age for adults over 40, which matches what lab tests show.
- Haskell & Fox: 220 − age. The best-known formula, and the simplest. It tends to underestimate max heart rate after about age 40.
- Nes et al.: 211 − 0.64 × age. From a study of more than 3,000 healthy adults in Norway (Nes et al., 2013). It reads a few beats higher than Tanaka.
All three are averages. Your own max can easily be 10 bpm or more away from any of them, which is why a measured max is better. Our guide to finding your actual maximum heart rate walks through a safe field test.
Zone Methods Compared
% of max heart rate. Each zone is a share of your max: Zone 2 is 60–69%, for example. It's simple, needs only one number, and is FITIV Pulse's default.
Heart rate reserve (Karvonen). Your reserve is your max minus your resting heart rate. Each zone is your resting heart rate plus a share of that reserve, using the same 50/60/70/80/90% steps. A 35-year-old with a max of 184 and a resting heart rate of 60 gets a Zone 2 of 135–146 bpm, compared with 111–128 bpm using % of max. Because it adds your resting heart rate, its zones run higher than % of max at the same percentages, and they're only as accurate as your resting number.
% of lactate threshold heart rate (LTHR). Your LTHR is roughly the highest heart rate you can hold for an hour of hard, steady effort, often estimated from the average of the last 20 minutes of a 30-minute all-out solo effort. In FITIV Pulse, the zones start at 65%, 80%, 89%, 95%, and 100% of LTHR. Because it's tied to your fitness, not just your age, it's popular with experienced runners and cyclists.
Example: Zones for a 35-Year-Old
Using Tanaka, 208 − (0.7 × 35) = 183.5, rounded up to a max of 184 bpm.
| Zone | % of max HR | Heart rate reserve (resting 60 bpm) |
|---|---|---|
| Z1 | 92–110 bpm | 122–134 bpm |
| Z2 | 111–128 bpm | 135–146 bpm |
| Z3 | 129–147 bpm | 147–159 bpm |
| Z4 | 148–165 bpm | 160–171 bpm |
| Z5 | 166–184 bpm | 172–184 bpm |
Use Your Zones in FITIV Pulse
FITIV Pulse sets your zones automatically from your date of birth, then shows your live zone during every workout on Apple Watch, iPhone, or a Bluetooth heart rate monitor. After each workout you get a time-in-zone breakdown, and your heart rate drives your Strain score and training load.
Frequently Asked Questions
How do I calculate my heart rate zones?
Start with your maximum heart rate, from a field test or a formula such as Tanaka (208 − 0.7 × age). Then multiply it by each zone's percentage: Zone 1 starts at 50%, Zone 2 at 60%, Zone 3 at 70%, Zone 4 at 80%, and Zone 5 at 90%. For a 35-year-old, Tanaka gives a max of about 184 bpm, so Zone 2 is roughly 111–128 bpm.
Which max heart rate formula is most accurate?
None of them is accurate for everyone, since real max heart rate can be 10 bpm or more above or below any formula. Tanaka (208 − 0.7 × age) and Nes (211 − 0.64 × age) come from larger studies than 220 − age and fit adults over 40 better. A max you've actually seen in a hard test or race beats every formula.
Should I use % of max heart rate or heart rate reserve?
% of max heart rate is the simplest and is FITIV Pulse's default. Heart rate reserve (the Karvonen method) also uses your resting heart rate, so your zones reflect your own range from resting to max. At the same percentages its zones run higher than % of max, and it needs an accurate resting heart rate, measured on waking.
What is my Zone 2 heart rate?
With % of max heart rate, Zone 2 is 60–69% of your max. Enter your age or known max in the calculator above to see your Zone 2 range in bpm. For most adults it lands somewhere between about 100 and 140 bpm, depending on age and max heart rate.
Do my heart rate zones change as I get fitter?
With % of max, your zones only change when your max heart rate does, which happens slowly with age. With heart rate reserve, they also shift when your resting heart rate drops. What changes most with fitness is what you can do inside each zone: you'll run or ride faster at the same heart rate.
