📐 Calibrations
Fan Channel Calibration maps the actual duty-to-RPM relationship for an individual fan, removing dead zones and saturation areas so CoolerControl can operate the fan within a consistent, predictable duty range.
After calibration:
- 1% duty represents the real minimum sustained RPM speed
- Reported duty values reflect the fan's actual RPM relationship rather than raw hardware-cached values
- Profile output translates accurately across the fan's true operating range
Requirements
Calibration is available only on fans and pumps that report RPM speeds. Stepped fans (e.g., ThinkPad laptops) are not eligible, their discrete operating steps make continuous duty mapping unnecessary.
How to Access
There are two entry points:
- Channel Settings page — open a fan channel, click on the Device Channel Settings icon, and click the calibration option.
- Controls page — click the calibration icon on a Fan Channel card.
Calibration Process
CoolerControl takes full independent control of the fan and sweeps through the duty range to record RPM at each point. When complete, a duty-RPM graph, or Calibration Curve, is available showing the full operational range and additional settings.
What gets detected and applied:
- Dead zones — duty ranges where RPM does not change are removed from the effective range.
- Saturation zones — duty levels where RPM tops out are trimmed from the upper end.
- Disconnected fans — if a fan shows no RPM response to any duty change, a diagnostic warning is reported.
TIP
Calibration may take longer for slow-responding fans. Let it run to completion for accurate results.
Update your Profiles after calibrating
Calibration remaps the fan's effective duty range. Any existing Profiles assigned to this channel were built against the old, uncalibrated range and will likely need to be reviewed and adjusted to reflect the new duty boundaries.
Post-Calibration Settings
After calibration completes, you can review and adjust the following settings:
Kick-in Boost
A fan stopped at low duty may need a brief burst of higher power to start spinning. CoolerControl detects this requirement during calibration and can apply an automatic kick-in boost whenever the fan restarts.
| Setting | Description |
|---|---|
| Enable / Disable | Toggle whether the kick-in boost activates when the fan starts from stopped. |
| Duration | How long the boost lasts before the fan transitions to its target duty. |
| Walk-down | Whether duty gradually steps down to the requested level (smoother) or drops immediately. |
True Duty Reporting
Once calibrated, the duty percentage CoolerControl displays for that channel reflects the fan's actual operating point based on its RPM curve - not the raw value written to the hardware. This makes comparisons between different fan models more meaningful and lets profiles behave consistently regardless of hardware variation.
RPM-only fans
Some hardware drivers report RPM speeds but no duty value. Calibrating these fans unlocks a derived duty reading, as CoolerControl calculates the current duty from the fan's RPM position on its calibration curve. This is a meaningful enhancement for such drivers: channels that previously showed no duty at all will now display an accurate reading.
See Also
- Controls — access calibration from the Controls page or channel settings
- Profiles — calibration makes profile duty output accurate for the real fan range
- Overlay Profiles — apply start/stop speeds at the profile level instead
- Hardware Support — check if your device supports RPM reporting