Target Heart Rate Calculator
Find your heart rate training zones using the Karvonen (HRR) method, percentage of max HR, or Joe Friel's lactate threshold model.
Measure first thing in the morning before getting up.
Train to your heart rate zones accurately
A GPS watch with optical heart rate monitoring lets you train to HR zones without a chest strap.
Garmin Forerunner 265
Displays real-time heart rate zone during runs and gives a weekly training load summary by zone.
View on AmazonGarmin Forerunner 255
Accurate wrist heart rate and zone alerts. Good value for runners building aerobic base.
View on AmazonHow the Target Heart Rate Calculator works
Three established methods are available. The Karvonen method uses Heart Rate Reserve (MaxHR − Resting HR), producing more personalised zones for trained runners. The simple % of MaxHR method is a good starting point. Friel's 7-zone model uses your Lactate Threshold HR (LTHR) and is the most race-specific approach for serious athletes.
Frequently asked questions
How do I find my maximum heart rate?
The most accurate method is a field test: warm up thoroughly, then run hard for 3 minutes, recover for 3 minutes, then run all-out for 1 more minute. Your highest reading is close to your MaxHR. Age formulas (such as 208 − 0.7 × age) are less accurate but useful when you don't have a measured value.
Which HR zone should I train in most?
Zone 2 (aerobic base) should account for around 80% of your weekly running. This is lower than most recreational runners expect. Hard sessions - threshold and interval work - sit in the remaining 20%.
What is LTHR and how do I find it?
Lactate Threshold HR is the heart rate at which your body starts accumulating lactate faster than it can clear it. To estimate it: run a 30-minute time trial at maximum sustainable effort. Your average heart rate over the final 20 minutes is approximately your LTHR.