Watching videos on a 4K gaming monitor

Hi there. I'm looking to upgrade to a 4K monitor, but I want to make sure that my anime and movies don't look terrible if I fullscreen them. I have the full edition of K-Lite so I have Madvr set as my renderer, does it scale properly so lower resolution videos look fine or great on a 4K monitor?

Thanks. Just wanted to ask before I made this purchase!

Yes, MadVR has excellent scaling. You can adjust scaling algorithms in its settings. A good choice for image scaling is NGU Anti-Alias Medium/High.