As the summary says, is the range of Magneto's powers mentioned anywhere?
How does it sound "between 628,743,036 million km and 928,081,020 million km apart"? (In astronomical units the distance varies from 4.2 AU to 6.2 AU.)
In the events of "Avengers vs X-Men" the one and only Magneto took the magnetic attraction energy from the big 'ol planet Jupiter (yes, the planet!) in order to fight Iron-Man. Which means its maximum known range of powers is the distance between the Earth and Jupiter.
Magneto powers are widely described and in often conflicting in the descriptions, so there is little documentation about the range of his powers. With that said, there are things writers typically infer about Magneto's abilities. Each writers interpretation of the character varies.
Since Magneto can find and access the magnetism from the Earth, anywhere ON the Earth, he has proven he can manipulate and even alter the magnetic field of the Earth, with considerable effort. He altered Earth's magnetic field permanently trying to reduce the range or effectiveness of Charles Xavier's (Professor X) telepathy ability, for example.
He is able to utilize or harness magnetic electromagnetic fields even at interplanetary ranges as he does during the AvX storylines. How he does this is NOT explained in any detail. We are forced to accept that interplanetary distances are no limit to his awareness or ability to manipulate electromagnetic phenomena.
Magneto can manipulate magnetic fields to generate powerful electromagnetic pulses and can even manipulate photons warping light around himself becoming invisible. He can manipulate the electromagnetic spectrum so that he may generate lightning bolts, emit vast amounts of infrared radiation or even manipulate the force of gravity.
He is capable of generating electromagnetic barriers capable of resisting nuclear weapons and can exist in deep space using these fields to protect himself from radiation. He is able to propel himself at near-light speeds. He has also been able to generate wormholes to travel through space, teleporting himself and others safely.