Target Heart Rate Calculator
Turn your heart rate zones into a plan you can run. Set a target HR range for today's session — recovery, fat-loss steady state, tempo, or intervals — and see exactly where to hold your effort.
How to use this calculator
Enter your age to generate your target heart rate windows for every type of session. Optionally add your resting heart rate and switch on the Karvonen method for ranges tailored to your fitness. Then work backward from your goal: pick the session you are doing today, find its window in the zones below, and hold your effort inside that band for the duration listed.
Reading your target zones
Each zone is a target heart rate range for a specific kind of effort, not a grade. The steady-state window (60–70%) is where most of your weekly volume should live because it builds aerobic fitness without piling on fatigue. The tempo and interval windows (80%+) are for one or two quality sessions a week. Pick the window that matches today's purpose and let it set your pace, rather than chasing a number that happens to feel "moderate."
Frequently asked questions
Picking a target heart rate for the workout in front of you
A training zone is only useful once you attach it to a purpose. Before a session, decide what you want from it, then pick the heart rate window that delivers that outcome. The mistake most people make is treating every run or ride as a "moderate" effort, which lands them in the unproductive middle ground all week. Match the session to a goal first, then let the target HR follow.
| Session goal | Target HR window | How it should feel | Typical duration |
|---|---|---|---|
| Recovery / shake-out | 50–60% max HR | Conversational, almost too easy | 20–40 min |
| Fat-loss steady state | 60–70% max HR | Relaxed, can speak in full sentences | 45–90 min |
| Tempo / "comfortably hard" | 76–84% max HR | Controlled discomfort, short phrases only | 20–40 min |
| Intervals / VO2 work | 88–95% max HR | Hard to very hard, near breathless | 30 sec–5 min reps |
| Neuromuscular sprints | 95%+ max HR | All-out, unsustainable | 10–30 sec reps |
The 80/20 idea, applied to your week
Polarized training keeps the bulk of your volume genuinely easy and reserves a small slice for genuinely hard work. The reason it works is that easy sessions build the aerobic engine without adding fatigue, while a handful of hard efforts drive the sharp adaptations. The trap is the "moderate" middle: hard enough to tire you out, not hard enough to force adaptation. A practical weekly target HR distribution for a recreational athlete training four to five times a week:
- ·Roughly four-fifths of your sessions sit at or below the fat-loss steady-state window (60–70% max HR) — keep these honestly easy
- ·Reserve about one-fifth for tempo or interval work in the 80%+ windows — one or two quality sessions per week is plenty
- ·A typical week might be three easy steady-state sessions, one tempo session, and one interval session
- ·Treat the recovery window (50–60%) as its own tool for the day after a hard effort, not as a "junk" pace to avoid
- ·If every session leaves you mildly tired, you are probably living in the middle — pull the easy days back and sharpen the hard ones
Mapping perceived effort to heart rate
You will not always have a monitor, and HR lags effort by a few seconds at the start of intervals. Learning to map the 1–10 rating of perceived exertion (RPE) scale to your zones lets you self-regulate by feel and cross-check your device when the numbers look off.
| RPE | Effort description | Roughly equals | Talk test |
|---|---|---|---|
| 1–2 | Very light, warm-up | 50–60% max HR | Could sing |
| 3–4 | Light, all-day pace | 60–70% max HR | Full sentences |
| 5–6 | Moderate, working | 70–78% max HR | Short sentences |
| 7–8 | Hard, tempo to threshold | 78–88% max HR | A few words |
| 9–10 | Very hard to maximal | 88%+ max HR | Cannot talk |
Strap vs. wrist: getting your target zone to actually mean something
Zone training falls apart if the numbers feeding it are wrong, and the failure mode is specific: optical wrist sensors tend to drift and lag exactly when you need precision, during intervals and sprints. For steady-state and recovery efforts, a wrist reading is usually close enough to keep you in the right window. For interval and tempo work, where you are chasing a tight target range, a chest strap removes the guesswork.
- ·Steady-state and recovery sessions: a wrist optical sensor is fine — your target window is wide and forgiving
- ·Intervals, tempo, and sprints: use a chest strap; wrist readings often under-read at the start of hard reps and over-read on cadence-locked efforts
- ·Watch for cadence lock, where the watch reports your step rate (e.g. a flat 170 bpm) instead of your pulse — a classic optical artifact
- ·Warm the sensor and snug the band before hard efforts; cold skin and a loose fit are the two biggest sources of bad readings
- ·When a number looks impossible for the effort, trust the talk test and your RPE over the screen