This is my code, based on this suggestion. Adjusting the size to 64 or 256 did not change the size of the object.

"QPushButton#pushButton_Calibration {image: url(:/images/toolkit_" + textColor + ".png); qproperty-iconSize: 128px;}"

This is my other code, based on this other suggestion. Adjusting the width/height to 64 or 256 did not change the size of the object.

"QPushButton#pushButton_Calibration {image: url(:/images/toolkit_" + textColor + ".png); width: 128px; height: 128px;}"

I am aware that something like this is an option:

ui->pushButton_Calibration->setIconSize(QSize(128, 128));

But I am unsure on how to implement this to something with the format QPushButton#pushButton_Calibration.

Please let me know if more information is required to solve this issue. I am unfamiliar with the syntax needed to change the size of the icon and haven't been able to locate it from the documentation.