Honestly, it's anyone's guess. The production teams for the anime and manga have their own considerations and timelines. Sometimes, they might deliberately keep a gap to maintain the excitement and longevity of the franchise.
There's no set answer. It all depends on how quickly the manga progresses and how the anime production team decides to adapt the story. Sometimes, they might slow down the anime to avoid catching up too soon.
The One Piece anime isn't fully caught up to the manga. There are still significant story arcs in the manga that haven't been animated. This is common in many long-running anime series.
It's tough to give you an exact chapter number because it keeps going. But you can easily get the latest info by visiting manga subscription services or popular manga discussion groups.