Another method I used is Guides.

1. Enable Guides. This option is found under View -> Guides -> Show guides

(Ctrl + Alt + E Ctrl + Alt + G)

2. Show Ruler. This option is found under View -> Show Ruler

3. Drag two horizontal guides and two vertical guides. Measure out their spacing on the ruler

4. Resize image according to the guides

Another method I used is Guides.

1. Enable Guides. This option is found under View -> Guides -> Show guides

(Ctrl + Alt + E Ctrl + Alt + G)

2. Show Ruler. This option is found under View -> Show Ruler

3. Drag two horizontal guides and two vertical guides. Measure out their spacing on the ruler

4. Enable Snap to Guide. This option is found under View -> Snap to -> Guide

5. Resize image according to the guides