You can subtract 56 years 8 months and 15 days to convert Hindu/Nepali calender in to English calender. For details, visit this link.
How Can We Convert Hindu Calendar Into English Calendar? I Want My Date Of Birth As Per English Calendar, Details Of Which Are As Follows: Tithi:Ekadashi, Month: Paush, Paksha: Shukla, Day: Tuesday, Vikram Sambat: 2017