In one example in accordance with the present disclosure, a method for determining fusing energy per page based on an applied voltage is described. According to the method, a resistance of a fusing system is acquired and an input voltage of a fusing system is estimated. A duty ratio of the fusing system is measured and a fusing energy per processed page is then determined based on the input voltage, the fusing system resistance, and the duty ratio of the fusing system. A media weight is then determined based on the fusing energy per processed page.