Sharp-crested weirs are commonly used for measuring flow in channels, but they have limitations. This study focused on developing a model to measure flow over inclined rectangular weirs. By increasing the inclination of the weir, the flow capacity also increases. A new index called the inclined-weir-discharging index was introduced to measure the flow capacity of the weir. The model provides an accurate way to predict flow over the weir, and increasing the inclined-weir discharging index can improve flow capacity and reduce afflux.