West Ham expect to have capacity crowds at nearly all of their matches at the Olympic Stadium, co-chairman David Gold has told BBC Sport.
The Hammers are preparing for their final season at the Boleyn Ground, with the fixtures released on Wednesday revealing Swansea will be the last Premier League visitors to Upton Park, in early May.
"Leaving the Boleyn Ground will be an emotional time. It will be a momentous event for anyone affiliated to the football club," said Gold, who grew up in Green Street, yards from the East London ground.
The Hammers will go from playing in front of 35,000 fans to the potential of nearly 20,000 more, so can they fill their new home?
"Obviously, attendances have a lot to do with performances on the field, but taking all things into account we are optimistic of filling the stadium, 99% of the time," said the 78-year-old, who owns the club with David Sullivan.
"Every time we get an update on ticket sales, they are the best we have experienced. All the targets we have set ourselves are being met."