Examples herein relate to monitor calibration. In some examples, monitor calibration can include a scaler processing resource and a memory resource storing machine readable instructions to cause the scaler processing resource to record, by a sensor included on a monitor, color measurements of the monitor in response to receiving record instructions from an external computing device, transmit the recorded color measurements to the external computing device, receive calibration instructions from the external computing device based on the recorded color measurements, and calibrate the monitor using the calibration instructions received from the external computing device.