You can use this tool to calculate the proportional dimensions of your image when you are enlarging or reducing its size for printing. We recommend you this calculator when you want to resize an image because it will help you preserve the original look.
How to use this tool
Enter the current width and height of your image
Enter the new dimension you know (this can be the new width or height)
The calculator will tell you the new proportional width or height, depending of what you entered on step 2