Some aviation research websites Quote approx 102465 average number of flights daily. All including small planes, private jets, helicopters etc, it goes to somewhere around 150000 a day. So bottomline is, around a Hundred Thousand Flights per day. read more
According to this blog post which cites a third-party report, on average there are about 100,000 scheduled commercial airline flights per dayworldwide. That's different than the number of airplanes -- since the same plane can fly multiple times in one day -- so the actual number of planes is probably in the 50,000-80,000 range. read more
Drew, Kris has given a good answer but the total of passenger flights each day is now about 60,000. However, you ask how many planes fly each day. That is a much lower figure as many planes do multiple flights during the day. This is especially true of the low-cost airlines. So about 25,000 airliners do around 60,000 flights per day. read more