There is potential for a further £6.85m in performance-related add-ons.
United last Friday announced they had secured a deal to bring the 36-year-old Portugal forward back to the club subject to the agreement of personal terms, a medical and a visa.
And Juve have now confirmed United are paying 15m euros for Ronaldo plus eight million euros (£6.86m) in potential add-ons, in a statement released early on transfer deadline day.
The statement said: “Juventus Football Club announces that an agreement with Manchester United FC for the definitive disposal of the registration rights of the player Cristiano Ronaldo has been reached for a consideration of 15million euros payable in five financial years, which might be increased, up to a maximum of 8m euros, upon achievement of specific performance objectives over the duration of the employment contract with the player.”
The five-time world player of the year, who was being linked with Manchester City prior to it emerging that he was set to head back to Old Trafford, is returning 12 years after leaving United for Real Madrid.
He had six seasons with the Red Devils that saw him score 118 goals in 292 appearances and help them win three Premier League titles, a Champions League the FIFA Club World Cup, one FA Cup and two League Cups.
Ronaldo then spent nine years with Real, during which he tasted Champions League glory a further four times and became the LaLiga outfit’s all-time top scorer, before moving to Juventus in 2018.