Heart Rate Zone Calculator

How do I calculate my heart rate zones?

Max heart rate is the simplest: each zone is a share of your maximum, from 50–60% for Zone 1 to 90–100% for Zone 5. If you do not know your maximum, 220 minus your age is the usual starting estimate, but it can be off by 10 beats or more either way, so a maximum you have actually seen at the end of a hard race is better.

Heart-rate reserve, also called the Karvonen method, takes your resting heart rate into account: the same percentages are applied to the gap between resting and maximum, then added back to resting. Fitter runners with a low resting heart rate get zones that sit a little higher, which usually matches how the effort feels.

Lactate threshold heart rate is the heart rate you can hold for roughly an hour of hard, steady running. A common field test is your average heart rate over the last 20 minutes of a 30-minute solo time trial. Zones built on threshold are the most individual, because they start from what your body did rather than a formula.

Which zone should most of my running be in?

Most easy and long runs belong in Zone 2, an effort where you can still talk in full sentences. A common framework is about 80% of weekly running at easy effort and 20% harder, with Zones 4 and 5 kept for intervals and races. Our Zone 2 running guide explains why easy running builds the aerobic base everything else sits on.

Why does my heart rate drift?

Heat, hills, dehydration, poor sleep, stress and caffeine all raise heart rate at the same pace, and wrist sensors can lag or jump. Treat a zone as a guide for the day's effort, not a target to hit at any cost. Use our running pace calculator when you would rather plan by pace.

General training education, not medical advice. If you have a heart condition, take medication that affects heart rate, or have symptoms during exercise, talk to a qualified clinician before training by heart rate.