Lactate Threshold Calculator
Scale your independently tested heart rate, pace, or power anchors into percentage-based training bands.
Scale your own threshold anchors into practical training bands. Heart rate, pace, and power each use the value you enter.
Threshold pace · optional
Use anchors from the same sport and recent testing. You only need one; clear values you do not know. Heart rate does not predict your pace or power here.
No account needed. Calculated in your browser.
Threshold heart rate
Threshold pace
Threshold power
Durable endurance
Controlled aerobic pressure
Comfortably hard
Hard steady anchor
Short-repeat pressure
Choose a band for the session’s purpose.
30-minute field test estimate. HR and power are rounded to whole units; pace to whole seconds. Shared band boundaries reflect the scaling convention.
From numbers to understanding
Enter your own threshold heart rate, pace, or power from recent sport-specific testing. Each entered anchor is scaled independently into percentage-based planning bands; the calculator does not infer one measure from another.
Choose whether the anchor came from a field test or from a known lab, coach, race, or device result.
Enter at least one threshold anchor: heart rate, pace, or power.
Use the threshold row as the hard-steady anchor, then adjust based on sport, terrain, heat, fatigue, and coach-tested zones.
No. A true lactate test measures blood lactate across stages or constant-load efforts. This calculator turns an existing threshold estimate into usable training bands.
For the field-test option, the calculator accepts the final 20-minute average heart rate from a 30-minute effort as an estimate. Enter separately tested threshold pace or power; these values are not derived from heart rate.
Yes. The calculator only shows bands for the anchors you enter, so you can use heart rate for running, power for cycling, or pace on repeatable flat routes.
Explore the ideas behind the numbers.
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Zone Training Log
A privacy-first training log for iOS and Android. Free to start. Yours to make personal.
