The Magpies have flirted with relegation for much of the season, and look as though they may only narrowly avoid slipping into the bottom three spots in the Premier League.
However, Shelvey believes their squad is better than West Ham United's, who sit fourth in the league.
The two teams meet at Newcastle this weekend.
He said, per Chronicle Live: "The squad we've got on paper, I don't think theirs is better than ours, to be honest.
"I think we've got a great squad, we just haven't performed to the level we can. It's only recently we've picked up a few better results.
"That's given us the belief to finish this season strong, then come back next season and kick on."