Hey elleana, I have the 39" 4k and viewing distance wise, on a windows desktop, around 60cm is perfect for me, thats with 125% ui scale. Think of it as a 20" 1080p screen, it has similar ppi to it. So its similar to how far u would sit with most other regular PC monitors. However, for gaming at 1080p, it would be nice to sit back around 1m due to the lower res and the size. Or if u play slower paced games like strat or turn based etc, then just run the games at 4k Heroes of M&M 6 looks amazing on 4k.