Around 92 billion light years across. Based on current rates of expansion and how far objects are likely relative to where they sent their light from. An object 14 billion light years away is likely about 40 or so billion light years further today.
But I'm to understand that the Universe is expanding in all directions faster than the speed of light. So any size measurement will always be inaccurate? Yes?
Right, but even if it's expanding faster than a few ly per year, the estimate is still somewhat accurate. To make matters worse. The farther away you go the faster it's expanding which makes objects at the edge of the visible universe traveling away from us the fastest.
This also means there's a dissonance in that beyond the local group most galaxies are unreachable without some form of ftl drive. In fact most galaxies we see today are currently beyond the visible horizon of the universe. In a few billion years, there will be nothing but a black void beyond our local cluster of galaxies. A handful of Islands in a vast black sea.