Cycling Heart Rate Zone Calculator
Turn your cycling lactate threshold heart rate into seven practical training zones for recovery, endurance, tempo, threshold, and high-intensity work.
Your threshold input
Enter a whole-number cycling LTHR from 60 to 240 bpm. The startup example uses 170 bpm.
Your cycling zones
159 – 168 bpm
Zone 4 is the sustained hard-effort band immediately below your LTHR.
For an LTHR of 170 beats per minute, Zone 2 is 138 to 151 bpm and Zone 4 is 159 to 168 bpm.
Complete zone table
| Zone | Training purpose | Percent of LTHR | Heart-rate range |
|---|
Whole-bpm limits are rounded into contiguous bands. Zone 5c has no calculated upper limit because it represents efforts above 106% of LTHR.
How to use the cycling heart rate zone calculator
What this calculator does
This calculator converts one cyclist-specific measurement – LTHR (lactate threshold heart rate) – into seven training bands. The bands help you translate a live heart-rate reading into an intended workout intensity: easy recovery, aerobic endurance, tempo, sustained threshold work, or short efforts above threshold. It is a planning and interpretation tool, not a medical test, a diagnosis, or a guarantee that a particular workout is appropriate for you. Heart rate can be influenced by heat, dehydration, fatigue, altitude, illness, caffeine, medication, sensor error, and cardiac drift, so use the numbers together with perceived exertion and the purpose of the session.
When to use it
Use the calculator when configuring cycling zones in a bike computer or training platform, reviewing whether an endurance ride stayed mostly in Zone 2, designing tempo or threshold intervals, or updating targets after a new threshold test. British Cycling describes an athlete-specific threshold test as the starting point for heart-rate-based cycling plans, and notes that heart rate responds too slowly to be the sole guide for very short sprint efforts. See its guidance on using threshold heart rate in cycling training plans.
How to calculate
- The calculator opens with a ready-to-use demonstration LTHR of 170 bpm. The displayed zones and the Excel workbook are immediately available.
- Replace 170 with your own cycling LTHR in the LTHR (lactate threshold heart rate) field. Enter a whole number from 60 to 240 using digits only; do not enter a percent sign, units, commas, decimals, or scientific notation.
- Read the live summary pills, the highlighted Lactate-threshold training band, the seven zone cards, and the Complete zone table. All views use the same current calculation.
- Select Download Excel to save the current input, results, zone definitions, and notes in a validated .xlsx workbook. Select Reset to clear the demonstration value and all calculated content. After Reset, Excel export is disabled until a complete valid LTHR is entered again.
Input guide
LTHR (lactate threshold heart rate) is the only input and is required. It is a whole-number heart rate in beats per minute (bpm), accepted from 60 through 240. A realistic example is 170 bpm. Raising LTHR shifts every zone boundary upward; lowering it shifts every boundary downward. Do not substitute an age-predicted maximum heart rate: LTHR and maximum heart rate are different measurements. A common field approach is a controlled 30-minute cycling time trial and the average heart rate from the final 20 minutes, but testing is demanding and should be done only when appropriate for your health and experience. TrainingPeaks provides background on threshold testing and setting cycling zones.
Output guide
LTHR repeats the accepted input. Endurance shows Zone 2, the range commonly used for steady aerobic rides. Threshold band and Lactate-threshold training band show Zone 4, the 94% – 99% band directly below threshold. Each zone card and each row in the Complete zone table reports the zone name, training purpose, percent band, and whole-bpm range. Zone 1 is displayed as “up to” its upper boundary, while Zone 5c is displayed as a lower boundary with a plus sign because it is open-ended. These outputs are estimates produced from fixed percentage bands; they are not individualized prescriptions beyond the LTHR you supply.
Worked example
With the startup LTHR of 170 bpm, the calculator sets the Zone 1 ceiling at 137 bpm. Zone 2 runs from 138 to 151 bpm, Zone 3 from 152 to 158 bpm, Zone 4 from 159 to 168 bpm, Zone 5a from 169 to 173 bpm, Zone 5b from 174 to 180 bpm, and Zone 5c begins at 181 bpm. For example, the Zone 4 upper limit is 99% of 170, or 168.3 bpm, displayed as 168 bpm. The adjacent whole-bpm boundaries are kept contiguous so every integer heart rate belongs to one zone.
How the seven-zone model works
The model uses the cycling-specific Joe Friel percentage pattern: Zone 1 below 81% of LTHR; Zone 2 through 89%; Zone 3 through 93%; Zone 4 through 99%; Zone 5a through 102%; Zone 5b through 106%; and Zone 5c above that level. TrainingPeaks lists the Joe Friel cycling method among its LTHR-based zone systems. Because a heart-rate monitor reports whole beats per minute, the calculator rounds zone limits and removes gaps between adjacent bands.
Interpreting each cycling zone
- Zone 1 – Active recovery: very easy spinning, warm-ups, cool-downs, and low-stress recovery rides.
- Zone 2 – Endurance: controlled aerobic riding that can be sustained for long periods when fueling and conditions allow.
- Zone 3 – Tempo: purposeful, moderately hard work that requires attention but remains below threshold.
- Zone 4 – Lactate threshold: sustained hard work typically used in structured intervals rather than all-day riding.
- Zone 5a – Above threshold: hard efforts just beyond LTHR, where fatigue accumulates quickly.
- Zone 5b – Aerobic capacity: short, demanding intervals aimed at high aerobic power and VO₂max development.
- Zone 5c – Anaerobic capacity: very short maximal or near-maximal work; heart rate often lags behind the actual effort.
Practical limits and safety
Heart rate is a relative intensity signal, not a direct measurement of power, speed, oxygen consumption, or lactate concentration. During short intervals, your legs may be working at maximal intensity before your heart rate reaches the corresponding band. During long rides, cardiac drift may move heart rate upward even if power stays constant. The CDC explains that exercise intensity can also be assessed with breathing and the talk test; its overview of measuring physical activity intensity is a useful cross-check when heart-rate data and perceived effort disagree.
Repeat a threshold test under similar conditions when training status changes materially, and keep cycling and running thresholds separate if your measured values differ. Stop exercise and seek appropriate medical help for chest pain, fainting, unusual shortness of breath, or other concerning symptoms. People with cardiovascular conditions or medications that alter heart-rate response should obtain individualized guidance from a qualified clinician.
This calculator provides educational estimates for exercise planning and does not replace medical evaluation, professional coaching, or laboratory testing.