Are the objects (or beings) something can be transformed into restricted by their current size and amount of matter? I seem to remember some transfigurations being done where a larger object was transformed into a smaller one, or a person was transformed into a smaller animal, such as a ferret.

Does the new object have to contain all the molecules and mass of the old object? If not, is there anything to indicate where that mass goes to? And if that smaller object is changed back to a large object (or any small object changed to a large object), where does the new mass in it come from?

While the Law of Conservation of Matter is science, I'm wondering if magic can bypass it.

  • For no reason what so ever this question made me think of Vapoorizer
    – Xantec
    Jan 21, 2012 at 2:33

3 Answers 3


JK Rowling has said that Transfiguration is a highly precise and scientific form of magic:

"I see Charms as a slightly lighter subject than Transfiguration. [Transfiguration] is harder work. Charms has a little bit of leeway for more personal creativity. Transfiguration you have to get exactly right, so it's much more of a scientific subject." JK Rowling - Mugglenet transcript of Q&A at Royal Albert Hall - 2003

I think that magic would have to fit in with our world in a way that works and is not disruptive. I do interpret canon as demonstrating magic as an energy force, one that must be channeled in various degrees of precision and power. I do think that elemental displacement and mass matters in Transfiguration and similar magic and Potterverse in general; if it didn't, there would be no Splinching. Splinching implies to me that someone wasn't able to properly channel the energy that is magic and, upon Apparating, they did not create a large enough receiving space to accommodate their whole body at their destination point. That said, I think it's possible that when magic energy is properly channeled, it allows for a fundamental adjustment in mass volume, allowing Transfiguration of an object or person from large to small, and vice versa.

  • Barty Crouch Jr. Transfigured Barty Crouch Sr. into a bone and buried him.
  • Barty Crouch Jr. as Mad-Eye Moody Transfigured Draco Malfoy into a ferret.
  • Horace Slughorn Transfigured himself into a chair.
  • Professor McGonagall, Sirius Black, Peter Pettigrew, James Potter, and Rita Skeeter change into Animagi, both larger and smaller than their natural state.
  • Hannah Abbott accidentally Transfigures a ferret into a flock of flamingos during her O.W.L.
  • Sirius and Remus Untransfigure Peter from his rat form to his human form.

I found an interesting page called Wizard Science: Transfiguration that says it better than I ever could.


I'm going to go with no. Presumably such a restriction would apply to animagi as well, and James turned into a stag, which was (almost certainly) much heavier than himself.

As far as where the mass goes, I'd imagine it goes into (and comes from) the same place objects vanished entirely do:

"Where do Vanished objects go?"
"Into non being, which is to say, everything," replied Professor McGonagall.


Perhaps the conservation of matter is accomplished through using the air around the wizard to increase the mass. There are 2.5x10^25 atoms of air around us at sea level. Maybe the air is sucked in to provide extra mass.

  • 1
    This seems to be just a personal opinion. We encourage answers that are backed by evidence. Dec 1, 2016 at 19:44

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