Equations & sources
Inspiral · leading post-Newtonian
chirp mass$\mathcal{M} = \dfrac{(m_1 m_2)^{3/5}}{(m_1 + m_2)^{1/5}}$
ISCO frequency$f = \dfrac{c^3}{6^{3/2}\,\pi G M}$
time to merger$\tau = \tfrac{5}{256}(\pi f)^{-8/3}\!\left(\dfrac{G\mathcal{M}}{c^3}\right)^{\!-5/3}$
strain (quadrupole)$h = \dfrac{4G\mathcal{M}}{c^2 d}\left(\dfrac{\pi G\mathcal{M}f}{c^3}\right)^{\!2/3}$
Remnant · nonspinning NR fits
final spin$a = 2\sqrt{3}\,\eta - 3.454\,\eta^2 + 2.353\,\eta^3$
radiated energy$E/M = 0.056\,\eta + 0.581\,\eta^2 - 0.960\,\eta^3 + 3.354\,\eta^4$
final mass$M_f = M\,(1 - E/M)$
Ringdown · Kerr quasi-normal mode
QNM frequency$M_f\,\omega = 1.5251 - 1.1568\,(1-a)^{0.1292}$
damping time$\tau = Q / (\pi f_{\rm ring})$
Sources: Maggiore Vol. 1 (PN inspiral); Rezzolla+ 2008 (spin); Jiménez-Forteza+ 2017 (radiated energy); Berti-Cardoso-Will 2006 (QNM). Validated against GW150914.