57/85 expressed as a percentage is 67.06%. This number tells you how much of a whole 57 parts out of 85 represent when you look at it on a scale of 100.
In everyday terms, 67.06% means that a little more than two‑thirds of something is covered or completed. If you imagined 85 pieces of a puzzle, having 57 of those pieces would fill about two‑thirds of the picture.
The percentage is rounded to the nearest two decimal places, so the exact value might be a tiny bit different, but for most purposes 67.06% is clear and easy to understand.