Talk:Sonic the Hedgehog vs. Meta Knight/@comment-27768589-20160819201251/@comment-26418719-20160819210958

Your math is sound, there. 16*60=960. 16 minutes would be 960 Rings.

But that only applies if we're using Game Mechanics and assume he has a maximal number of rings. If we're using feats from outside of gameplay, he can maintain the form for multiple weeks, as he showed in Sonic Advance's ending.