Viewgrader is a simple tool for the calculation of the edges of the movie frame for proportional scaling. In the case of proportional resizing video frame to scaling width, height must be scaled by the same aspect ratio. Conversely, scaling the height, width must be scaled by the same scale factor. The program calculates the aspect ratio after scaling one edge, for scaling another frame edge.

Example of use:
In a situation where we are scaling the video frame size of 320 x 220 pixels to the size of 280 pixels in width, it is necessary to reduce the height to proportional size.