The best available answer from cosmologists is that the universe is somewhere just shy of 14 billion years old. Some answers given are remarkably specific, some are ranges, but there seems to be some general consensus that converges, more or less, on this number.
https://www.space.com/24054-how-old-is-the-universe.html
https://map.gsfc.nasa.gov/universe/uni_age.html
https://books.google.com/books/about/Origins_Fourteen_Billion_Years_of_Cosmic.html?id=m0_LGjZkxpQC&source=kp_cover
However, that answer is almost certainly incorrect, and is, as is the question itself, somewhat meaningless.
First, as we run back the clock on the universe, all the mass in the universe occupied less 3D space (and more MD space). Forgetting for a moment that it never got to a point (there’s no such thing as a singularity), when it was all squished together (please excuse the technical jargon), time did not run at the same speed as it runs for us now and here. In fact, time doesn’t run at the same speed almost anywhere, but in the early universe it would have run extremely slowly. Like, A LOT more slowly. Such that our frame of reference has no real meaning.
Speaking of a frame of reference, whether it be a pendulum, the regular decay of large elements, things rotating around each other at regular intervals, any way we can conceive of to track time wouldn’t have been available to us in the high density, primordial soup that was the early universe. So, even if time was elapsing the way it does now (there was time as we sort of know it), we couldn’t have measured it, and even if we could, it would be running on a scale we can’t really understand (we have no way to measure how the extreme warping of MD space might have altered time).
The longer ago something emitted light that we can capture today, the more warped MD space was and, relatedly (probably), the slower time was. The 14 billion years number more or less assumes that the light was travelling the same distance in the same time the whole of the 14 billion years, but cosmologists know (or should know) that’s not true.
Second, at least to the extent the 14 million years answer is based on the Hubble constant, it’s wrong because the Hubble constant is wrong (which is somewhat related to the above, but all the bits of the universe we can experience are held together with a common set of underlying properties, so everything is related to everything…)
It’s right there in the name – the Hubble Constant. It assumes that the speed of light is a constant and that the universe is 3D. But we know that’s not true. Even now, the universe is MD and it was more MD the further away any object is (the longer the light took to get to us). The speed of light may be a constant in MD space, but since light has to travel more distance in MD space (in order for our brains not to hurt, we think of this as ‘curvature’) than it would travel in 3d space, and space was more MD in the distant past than it is now, than the speed of light as measured in a 3D frame of reference can’t possibly be a constant.
Even for nearer objects (whose light was emitted when the universe was closer to the average level of MD warping that we experience today), it is still be the case that the further something is from us the more bumpy the path the light took. We’d experience some amount of redshift even if the universe wasn’t expanding and at least some of that shift would actually describe not the speed of recession but the degree of MD warpage.