Get your desired fullscreen 4:3 aspect ratio height by entering the desired width for the image or video you want to resize.
The 4:3 Aspect Ratio is commonly known as the fullscreen aspect ratio. The 4x3 (1.33:1) format became the first standard ratio for televisions and computer monitors as it was easy to use due to the camera formats.
Back in the days, there was plenty of video and movies recorded in the 4:3 aspect ratio, so they didn't need to be converted for the TV release. It was first later in the 1990s and 2000s the widescreen 16:9 ratio became more popular as a video ratio format.
Based on desktop resolution statistics from August 2020, the XGA fullscreen (1024 x 768) is still getting used a lot today.