Heart Rate Zone Calculator

Calculate your personalised heart rate training zones using the Karvonen formula, % Max HR or Zoladz method. Runnify uses an 8-zone model based on % of max heart rate — from active recovery to lactic power — so every session has a clear purpose. Download the Runnify app to automatically get your heart rate, pace and RPE zones tailored to your level — combining these three metrics is the most accurate way to control training intensity.

Calculation method
Recommended

Recommended — uses your Heart Rate Reserve (Max HR − Resting HR) for the most personalised zones.

Formula: Target HR = ((Max HR − RHR) × %Intensity) + RHR

Simple percentage of your maximum heart rate. No resting heart rate needed.

Formula: Target HR = Max HR × %Intensity

Subtracts fixed bpm values from Max HR to define zone boundaries.

Formula: Target HR = Max HR − Zone adjuster (bpm)
Age
years
Used to estimate Max HR if not provided.
Maximum Heart Rate (Max HR)
bpm
Leave blank to estimate from age. A lab VO₂ max test or field test gives the most accurate Max HR.
Max HR estimation formula
Resting Heart Rate (RHR)
bpm
Measure first thing in the morning while still in bed. Required for Karvonen.
Activity level
Only used if you don't know your RHR — select your level to estimate it.

Your heart rate training zones

Zone Heart rate % max HR % VAM pace RPE Purpose
Compare all methods

See how your zones differ across calculation methods.

Zone Karvonen % Max HR Zoladz

Get your zones automatically with Runnify

Download the app and complete the VAM test included in Runnify. You'll get heart rate, pace and RPE zones personalised to your fitness — updated as you improve.

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Heart rate zone training guide

How Runnify's 8-zone model works and frequently asked questions

What are heart rate training zones?

Heart rate training zones are ranges of heart rates that correspond to different exercise intensities. Each zone targets specific physiological adaptations — from fat burning and aerobic base building to lactate threshold and maximal oxygen uptake.

Runnify uses an 8-zone system based on your VAM (maximal aerobic speed) test. This calculator estimates heart rate ranges from % of max HR; in the app, pace and heart rate targets are calculated automatically and updated as you improve.

How the Karvonen formula works

The Karvonen formula (Heart Rate Reserve method) accounts for your resting heart rate — something simpler methods ignore. A fitter runner with a lower RHR gets different, more appropriate zone boundaries.

Target HR = ((Max HR − Resting HR) × %Intensity) + Resting HR

Lab testing (VO₂ max test) remains the gold standard for the most precise max heart rate and individualised zones.

Three calculation methods

Karvonen — most accurate for individuals; needs resting heart rate. % Max HR — simplest; multiplies max HR by zone percentage. Zoladz — subtracts fixed bpm values from max HR. All three use Runnify's 8-zone % max HR definitions for Karvonen and % Max HR; Zoladz uses its own bpm-band structure mapped to 8 zones.

Why use Runnify for your zones?

This calculator gives useful estimates. In the Runnify app, zones are generated automatically from a VAM field test — heart rate, pace (% VAM) and RPE ranges personalised to you. Your plan adapts as fitness improves, so easy days stay easy and hard sessions hit the right intensity.

How to use your zones

  • Z1–Z2 (70–84% max HR) — 70–80% of weekly volume. Build aerobic base without excessive fatigue.
  • Z3 (85–89%) — Steady endurance and controlled long runs.
  • Z4 (92%) — Tempo and threshold development.
  • Z5 (96%) — Supra-threshold work for 5K–10K performance.
  • Z6 (100%) — VO₂ max intervals of 3–5 minutes.
  • Z7–Z8 — Pace-based zones for short reps, strides and sprints.

Frequently asked questions

The Karvonen formula calculates target heart rate using your Heart Rate Reserve (Max HR minus Resting HR): Target HR = ((Max HR − RHR) × %Intensity) + RHR. It is more accurate than simple % of max HR because it accounts for your fitness level through resting heart rate.

For max HR, use a supervised test or the Tanaka formula (208 − 0.7 × age). A field test — three hard 3-minute hill repeats, recording peak HR on the last — also works well. For resting HR, measure first thing in the morning before getting up; average 3–5 mornings.

Runnify's 8-zone model aligns with our VAM-based training system: finer granularity from recovery (Z1) through aerobic base (Z2–Z3), threshold (Z4–Z5), VO₂ max (Z6) and anaerobic/sprint work (Z7–Z8). Zones 7 and 8 are primarily pace-based (% VAM).

Karvonen is recommended if you know your resting heart rate. % Max HR is simpler and works well if you know your actual max HR. Zoladz offers an alternative bpm-subtraction approach. In the Runnify app, zones are calculated automatically from your VAM test.

Zones 7 and 8 in Runnify's model are defined by % VAM pace (105–120%) rather than % max HR, because anaerobic and sprint efforts exceed what heart rate alone captures reliably. Use pace or RPE for these sessions; the app calculates all three metrics together.

Recalculate every 4–6 weeks or after significant training blocks. As fitness improves, resting heart rate typically decreases, shifting Karvonen zones. Max HR changes slowly with age (~0.7 bpm per year). Runnify updates your zones automatically as you progress.
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