From CBS News:
“A senior U.S. military official for the first time says the U.S.-led coalition has killed 50,000 militants with the Islamic State of Iraq and Syria, or ISIS, in the last two years in Iraq and Syria.
The official said it was a conservative estimate, but it’s a bit more than what others have stated before. U.S. leaders have expressed reluctance to disclose specific numbers, and note that ISIS has been able to replace fighters rapidly, particularly early on.
In August, Lt. Gen. Sean MacFarland said about 45,000 combatants have been taken off the battlefields.”