According to the manga, SSJ3 Gotenks around mach 2330 (he travelled around the earth at least 3 dozen times within 30 minutes)
BOG SSJ3 Goku is around the same level as SSJ3 Gotenks, so he should be at least as fast.
SSJ3 Goku is 1% of Bills in power
So by powerscaling Bills is at least mach 230000 (1/4 speed of light)
This is simple powerscaling, not regarding power level from scouter
(If you don't believe in powerscaling, please ignore DBZ threads)
BOG SSJ3 Goku is around the same level as SSJ3 Gotenks, so he should be at least as fast.
SSJ3 Goku is 1% of Bills in power
So by powerscaling Bills is at least mach 230000 (1/4 speed of light)
This is simple powerscaling, not regarding power level from scouter
(If you don't believe in powerscaling, please ignore DBZ threads)