Heart Rate Zones Calculator
Use this heart rate zones calculator to estimate training zones from either maximum heart rate or threshold heart rate.
Threshold heart rate generally provides more accurate training zones because it reflects your current fitness and sustainable effort rather than an estimated maximum value.
Estimate Maximum Heart Rate
Age
Estimated maximum heart rate: --
Zone Calculator
Method
Heart Rate
Zones based on --
How Heart Rate Zones Work
Heart rate zones divide your training intensity into bands, each of which produces a different physiological stimulus. Training in the right zone at the right time is one of the most important factors in structured endurance training - and one of the most commonly misunderstood.
Most endurance athletes benefit from spending the majority of their training time at low intensity - Zone 1 and Zone 2 - where aerobic capacity is developed without generating significant fatigue. Higher intensity zones (Zone 4 and 5) are valuable but should represent a minority of total training volume.
Maximum Heart Rate vs Threshold Heart Rate
The calculator accepts either your maximum heart rate (MHR) or your lactate threshold heart rate (LTHR) as the input. Both approaches are valid, but they produce zones using different models.
Maximum heart rate zones express each zone as a percentage of your MHR. If you don't know your MHR accurately, age-based estimates (such as 220 minus age) are notoriously unreliable - individual variation is large. A better approach is to find your MHR through a field test or to use your threshold heart rate instead.
Threshold heart rate zones are based on your heart rate at lactate threshold - the intensity you can sustain for approximately 60 minutes of maximal effort. This is a more reliable anchor point for zone calculation and is the approach used by many coaching platforms, including TrainingPeaks.
How to Use Your Zones in Training
Once you have your zones, use them to guide the intensity of each session. Your easy runs should sit in Zone 1 to 2 - genuinely easy, where you can hold a conversation without difficulty. Threshold work sits in Zone 4. True race pace and high-intensity intervals may push into Zone 5.
If you find that most of your 'easy' runs are creeping into Zone 3, you are likely training too hard on your recovery days and not hard enough on your quality sessions. This is one of the most common training errors in amateur endurance sport.
Want to make sure your training zones are set correctly and applied properly? The Performance Lab Lite session at stevebarbour.com includes a field-based threshold assessment and zone calibration.