Cycling Heart Rate Calculator

Enter your basics, then choose a zone or a custom intensity range.

These sample scenarios show how the target range changes by inputs.

This calculator supports two common ways to build heart-rate targets:

• Percent of max HR: Target HR = HRmax × (% / 100)
• Heart rate reserve (Karvonen): Target HR = HRrest + (HRmax − HRrest) × (% / 100)

If you do not provide max HR, it is estimated by one of these:

• HRmax = 220 − age
• HRmax = 208 − 0.7 × age

1. Enter your age and resting heart rate.
2. Optionally add a measured max heart rate for accuracy.
3. Select a calculation basis: reserve-based or max-based.
4. Choose a zone or set a custom intensity range.
5. Press Calculate to see targets and zones above the form.
6. Add duration and average HR to estimate TRIMP.

Why cycling heart-rate zones matter

Cycling intensity is easiest to control when effort is tied to a repeatable metric. Heart rate responds to oxygen demand, so zone targets help you pace endurance rides, long climbs, and structured intervals. Many riders aim to keep most weekly minutes in lower zones for aerobic development, then add small, planned doses of higher intensity to raise sustainable power. Because heart rate lags sudden surges by 30–90 seconds, use power changes and cadence when testing a zone.

How the calculator builds your target range

The tool first selects a maximum heart rate: either your entered value or an age-based estimate. It then applies one of two methods. Percent-of-max multiplies HRmax by the chosen intensity band. Heart-rate reserve uses resting heart rate to personalize the range, adding a percentage of (HRmax minus HRrest) back onto HRrest. The default cycling bands shown here span Z1 50–60%, Z2 60–70%, Z3 70–80%, Z4 80–90%, and Z5 90–100%.

Reading the zone table for training decisions

Zones are displayed as low and high beats-per-minute boundaries. Z1 and Z2 are typically used for warmups, recovery, and steady endurance. Z3 supports tempo work that feels “comfortably hard.” Z4 targets threshold efforts where breathing is heavy but controlled. Z5 represents short, demanding work that is difficult to hold for long. For interval sessions, start each repetition below the upper limit and let heart rate settle before pushing.

TRIMP adds a simple training-load number

If you enter ride duration and average heart rate, the calculator estimates TRIMP, a workload score that scales with time and intensity. It uses the fraction of heart-rate reserve as an intensity factor and applies an exponential term so higher efforts count disproportionately. Track TRIMP across weeks to balance progress and recovery. Gradual increases and planned deload weeks help manage fatigue overall.

Improving accuracy and day-to-day use

For best precision, use a measured HRmax from a hard test or lab assessment, and capture resting heart rate on multiple mornings. Expect heart rate to drift upward in heat, dehydration, fatigue, or long rides, so combine zones with perceived exertion. When in doubt, stay slightly below the upper boundary to keep pacing.

Should I use heart-rate reserve or percent of max?

Heart-rate reserve accounts for your resting rate, so targets often feel more personalized. Percent of max is simpler and works well if HRmax is accurate. Compare both with perceived exertion and choose the one that matches your sensations.

Why does my heart rate drift upward on long rides?

Cardiac drift can occur with heat, dehydration, fatigue, or low fueling. If you see rising bpm at the same effort, reduce intensity slightly, improve cooling, drink regularly, and use perceived exertion to stay in the intended zone.

Can I apply these targets on an indoor trainer?

Yes. Indoor sessions may show different heart-rate responses due to cooling and airflow. Use a fan, keep room temperature stable, and validate zones with a steady effort test so the displayed bpm range matches your trainer workouts.

How should I measure resting heart rate?

Measure after waking, before caffeine, while relaxed and still. Take 60 seconds using a strap, watch, or pulse count. Record several mornings and use the average to reduce day-to-day variability.

Why is the TRIMP value missing?

TRIMP is calculated only when both duration and average heart rate are entered. The average must be above resting heart rate to create a valid intensity factor. Enter your ride average and minutes, then recalculate.

How often should I update my max heart rate?

Update if you complete a new maximal test, return after a long break, or notice zones feel consistently off. For many riders, reassessing every few months during a training cycle is enough, unless health changes occur.