I used it to create a full-bleed utility class: .full-bleed { width: 100vw; margin-left: calc(50% - 50vw); }

Use-case party I asked some CSS developers when they last used calc() so we could have a nice taste here for for how others use it in their day-to-day work.

You can read more about properly sizing the text using a combination of units along with the the calc() function in this excellent article about viewport unit-based typography.