What was the peak Classic Mayan population?

close to 20 million, probably 17-18 million at the peak. It got to the point they couldn't feed everyone, and prayed for help from the gods for more food. When it did'nt come, they started offering human sacrifices, which of course still didn't work. Eventually they were wiped out by famine and the Spanish conquistadors, who spread viruses and smallpox which they didn't have an immune system capable of fending them off.

Mayan Population Peak

Historical demography experts speculate that in the VIII century, in full splendor of the Classical Period, the Maya population may have come to the thirteen million people. Maya's territory embraced almost all Guatemala, western Honduras, Belize, and the current states of Yucatan, Quintana Roo, Campeche, Chiapas and part of Tabasco, Mexico.

nobody knows they are all dead. we know from experience dead people don't talk