If you mean everything that makes up the observable universe by ‘universe,’
If we understand correctly, its radius after initial inflation was (approximately) 10 cm, the size of your fist. That’s in comparison to the current 14 billion light years.
Before and after inflation, how big was the universe?
Again, this is the observable Universe; the true “size of the Universe” is undoubtedly considerably larger than what we can see, but we have no way of knowing how much larger. Our best estimates, based on the Sloan Digital Sky Survey and the Planck spacecraft, suggest that if the Universe does curve back in on itself and collapse, the part we can see must be at least 250 times the radius of the viewable section to be indistinguishable from “uncurved.”
In fact, it may be unlimited in scope, as we have no way of knowing what the Universe was like before inflation, with everything save the final small fraction of a second of inflation’s history being wiped clean from what we can witness by the nature of inflation itself. However, if we’re talking about the observable Universe, and we know we can only access the last 10-30 and 10-35 seconds of inflation before the Big Bang, we know the observable Universe is somewhere between 17 centimeters (for the 10-35 second version) and 168 meters (for the 10-35 second version) in size at the start of the hot, dense state we call the Big Bang.