The numbers of people sacrificed by the Aztecs is a mystery today and will probably remain a mystery, unless more archeological evidence is uncovered. Whether only a few thousand of victims were sacrificed each year, or 250,000 as some scholars say, few human remains such as bones have been found at Templo Mayor or other Aztec temples. A couple of dozen skeletons and a few thousand loose bones and skulls do not add up to 250,000 or 20,000 or whatever number is cited.
Evidence of human sacrifice comes from both the Aztecs themselves, their art and codices containing their writings, and from the Spanish conquerors. However, it is safe to say that the Spanish could easily have exaggerated the numbers killed to make the Aztecs seem more savage and brutal than they actually were.
In 1487, the great Templo Mayor was dedicated in the main Aztec city of Tenochtitlan with a four-day celebration. How many were sacrificed during that time is a subject of scholarly speculation: some put the figure as low as 10,000 or 20,000, several others put it as high as 80,400 people sacrificed during those four days. Scholars think the Aztec priests used four sacrificial altars for the dedication ceremonies. However, if that’s the case and 80,400 people were killed, then the priests would have had to sacrifice 14 people every minute, which is a physical impossibility.
Spanish missionaries sent to convert the Aztecs to Christianity learned the Nahuatl language spoken by the Aztecs. These priests and friars spoke to old Aztecs to learn their history. These Aztecs put the number of sacrificial victims at the time of the temple’s dedication at 4,000, a much lower total than 80,400.
With scant archeological evidence, it is hard to know how many Aztecs died under the sacrificial knife. Many reputable scholars today put the number between 20,000 and 250,000 per year for the whole Aztec Empire. All Aztecs cities contained temples dedicated to their gods and all of them saw human sacrifices. Whatever the total was, we know from both the Aztecs and the Spanish that many human beings lost their lives to human sacrifice. We will probably never know exactly how many.