Free tool
Heart rate zone calculator.
Get your five training zones from your age or max heart rate. Add your resting rate for the more accurate Karvonen method.
What the five zones mean
| Zone | % max HR | Feels like |
|---|---|---|
| Z1 · Recovery | 50-60% | Very easy, active recovery |
| Z2 · Aerobic | 60-70% | Conversational, base-building |
| Z3 · Tempo | 70-80% | Comfortably hard |
| Z4 · Threshold | 80-90% | Hard, sustainable in blocks |
| Z5 · VO2 max | 90-100% | Maximal, short intervals |
Prefer to train by pace? Get your running training paces from a recent race.
Frequently asked
How do I calculate my heart rate zones?
The simplest way is as a percentage of your maximum heart rate. Estimate max HR as 220 minus your age, then take bands: Zone 1 is 50-60%, Zone 2 60-70%, Zone 3 70-80%, Zone 4 80-90%, and Zone 5 90-100%. The Karvonen method refines this by also using your resting heart rate, which personalises the zones to your fitness.
Is 220 minus age accurate for max heart rate?
It is a rough estimate that can be off by 10-20 beats for an individual. The most accurate max HR comes from a hard field test or a race where you hit your true ceiling. If you know your real max, enter it directly for better zones.
What is the Karvonen method?
Karvonen calculates zones from your heart rate reserve (the gap between your resting and maximum heart rate) rather than max HR alone. It gives more personalised zones because two people with the same max HR but different resting rates have different aerobic fitness.
Which zone should I train in most?
For endurance, most of your training should sit in Zone 2, the aerobic base that builds your engine with low injury risk. A smaller share of harder Zone 3-5 work sharpens fitness closer to a race. Getting that balance right, week to week, is what a structured plan handles for you.
Zones into a plan
Your zones, spent wisely.
Gritup assigns every run, ride, and swim a target zone and balances your week, so your easy days stay easy and your hard days build real fitness.