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HEALTH & FITNESS

Heart Rate Zone Calculator

Calculate your training heart rate zones for endurance, tempo, threshold, and VO₂ max work. Tanaka or Fox formula, with optional Karvonen reserve method.

  • Runs in your browser
  • Private processing
  • No uploads
Your data
yr
Training zones
Enter your age to calculate training zones

01Why this zone tool

Train with intent.

Four reasons runners, cyclists, and triathletes use this page to set up their watch and their workouts.

  • 01

    Five training zones, instantly

    Recovery, endurance, tempo, threshold, and VO₂ max — each with a clear bpm range derived from your max heart rate.

  • 02

    Tanaka or Fox, with optional Karvonen

    Pick the max-HR formula you trust. Add a resting heart rate to switch to the Karvonen reserve method for personalized zones.

  • 03

    Built for runners, cyclists, and lifters

    The zone definitions match what Polar, Garmin, and Strava use. The math you set here lines up with what your watch shows.

  • 04

    All computed in your browser

    Age, resting heart rate, and the zone table never leave your device.

02How it works

Age, resting, zones.

  1. Formula
    TanakaFox

    Step 1Enter your age

    Used to estimate your max heart rate. The tool defaults to Tanaka (208 − 0.7 × age), the most validated modern formula.

  2. Your data
    Age32yr
    Resting HR58bpm

    Step 2Optionally add resting heart rate

    If you know your morning resting HR, add it to enable Karvonen — the more accurate, personalized method.

  3. Max HR186bpmZ1 – Z5 ready

    Step 3Read your zones

    Five rows: recovery (Z1) through VO₂ max (Z5). Each shows the bpm range for that training intensity.

03Use cases

Where zones shape training.

Easy runs, threshold blocks, VO₂ days — anywhere intensity has to be deliberate.

  • Plan an easy run

    Z2 endurance is where the magic of aerobic development happens. Set your zone so 'easy' actually stays easy.

    Easy run · keep HR in Z2

  • Threshold intervals

    Z4 is sustainable hard effort. Pick the upper bound, hold it for 8 × 4 min on the bike, build threshold over weeks.

    Bike intervals · Z4 target

  • Recovery rides and runs

    Active recovery sessions belong in Z1. The tool shows the cap so you don't accidentally turn recovery into a workout.

    Z1 ceiling · 60% of max

  • Calibrate your watch

    Garmin and Polar default zones can be off if you haven't set max HR manually. Use this output to enter accurate ranges in the device app.

    Device zone config

  • VO₂ max workouts

    Short hard reps in Z5. Knowing the bpm window helps avoid 'too-easy hard days' and 'too-hard easy days' — both kill consistency.

    VO₂ session · Z5 reps

  • Coach-client handoff

    Sending a training plan to an athlete? Include their zones in bpm so 'tempo' or 'threshold' means the same thing on both sides.

    Plan attachment · zones table

04Quick tips

Use zones well.

Four habits that turn the table into actual training adaptations.

  • 01

    Karvonen is more personal than Tanaka

    Tanaka estimates max HR from age alone; Karvonen adjusts using your resting HR. If you have an accurate resting number, enable it.

  • 02

    Formulas are estimates

    Real max HR can differ from the formula by 10+ bpm. If you have a measured max from an all-out test, plug it in directly.

  • 03

    Resting HR drifts with fitness

    As cardio improves, resting HR drops — sometimes 10 bpm in a year. Re-check every few months and refresh your zones.

  • 04

    Most miles belong in Z2

    Polarized training calls for ~80% of volume in Z1–Z2 and ~20% in Z4–Z5. Knowing the boundaries makes the distribution real.

05Loved by

Runners, coaches, and triathletes.

  • Re-calculate zones every season after I retest resting HR. Garmin gets a fresh config and my easy days actually stay easy.
    Elias M.
    Marathon runner
  • Plug in a new client's data, screenshot the table, paste into their training doc. Three minutes start to finish.
    Ada P.
    Cycling coach
  • Tanaka + Karvonen for run and bike zones. Quick reference when I'm setting up the next training block.
    Hiroshi K.
    Triathlete

06Questions

Zones, plainly answered.

Questions before your first table. Missing one? hello@wirelogs.com.

01What's the difference between Tanaka and Fox formulas?

Both estimate max heart rate from age. Fox is the classic 220 − age (simple but inaccurate beyond ~35). Tanaka (208 − 0.7 × age) is the modern replacement, based on a meta-analysis of >18,000 subjects.

02What is the Karvonen method?

An adjustment that uses your heart-rate reserve (max minus resting) instead of just max HR. It produces more personalized zones for trained athletes whose resting HR diverges from average.

03Which zone should I train in most?

Most volume — typically 70–80% — should be Z1 to Z2 (easy aerobic). Z4 and Z5 work belongs in smaller, structured doses. Z3 is a 'gray zone' most coaches dial down.

04How do I know my real max HR?

A supervised maximal-effort test gives the most accurate value. Race finishes (hard 5K) often produce numbers very close to true max. Watch-detected 'max' is unreliable without an explicit test.

05Does my data leave the browser?

No. Calculations are all local.

06Is it free?

Yes. No sign-up, no usage cap, no watermark.

07Related tools

Other training calculators.

Heart rate zones sit next to pace, 1RM, TDEE, and the rest of the fitness math.

Ready when you are

Set your zones.

Enter your age (and optionally resting HR) above. The five-zone table appears instantly.

Open the calculatorBrowse all tools
  • Z1 – Z5five zones
  • Tanaka · Karvonentwo methods
  • $0now and always