  Gravitational waves emitted during the merger of two black holes carry
information about the remnant black hole, namely its mass and spin. This
information is typically found from the ringdown radiation as the black hole
settles to a final state. We find that the remnant black hole spin is already
known at the peak amplitude of the gravitational wave strain. Using this
knowledge, we present a new method for measuring the final spin that is
template independent, using only the chirp mass, the instantaneous frequency of
the strain and its derivative at maximum amplitude, all template independent.
