Systems, methods, and computer-readable storage media for calculating scaling ratios are described. An example method can include obtaining a current picture of video data and one or more scaling windows associated with the current picture and/or a reference picture selected for use in coding the current picture; determining a first size of the current picture and/or a second size of the reference picture, the first size including a first height and a first width and the second size including a second height and a second width; based on the one or more scaling windows and the first size and/or the second size, determining one or more scaling ratios associated with the current picture and/or the reference picture.