The observable universe is about 93 billion light-years in diameter, meaning the distance from Earth to the edge of the observable universe is roughly 46 billion light-years in every direction. This enormous size arises because the universe has been expanding since the Big Bang about 13.8 billion years ago, so distant objects have moved much farther away since they emitted the light we now see. However, this "observable universe" includes only the part of the universe from which light has had time to reach us, limited by the speed of light and the age of the universe. Beyond the observable universe, the true size of the entire universe is not known. Some scientific estimates suggest the entire universe could be at least 250 times larger than the observable universe, potentially spanning trillions of light-years or even being infinite in size. But this remains uncertain with current knowledge.

Key Points:

• Diameter of observable universe: about 93 billion light-years.
• Radius (distance to edge): about 46 billion light-years.
• Observable universe is limited by light travel time and cosmic expansion.
• True size of the whole universe unknown; possibly vastly larger or infinite.
• The observable boundary differs from the entire universe size due to cosmic expansion and limits on observation.

This reflects the vastness of the universe we can observe compared to the possible enormity beyond what we can see, shaped by the finite speed of light and cosmic history.