Answer from our Expert:
The entrance tickets for Machu Picchu in 2020 will remain the same as in 2019; US$46 for the normal entrance ticket and US$61 including either Huayna Picchu or Montaña. For children under 8 years of age the entrance is free and children between 8 and 12 years of age pay US$21 and US$36 for the ticket that includes Huayna Picchu or Montaña. These prices are calculated with an exchange rate of US$1 = S/.3.32 and are the prices for foreign visitors.
https://www.machupicchu.gob.pe/inicio