The 24-year old spent two years with Sporting, scoring 38 goals in 50 appearances and he will officially complete his move to the Canaries on July 1st.
Van Wolfswinkel has been selected in the Holland squad for their tour of Asia next month and he believes that English football will continue to help him progress.
"Some people may see my transfer as a step back," he said.
"But the Premier League is bigger than the Portuguese league. Life is good in Portugal, but the football has to be on a certain level too.
"Sporting ended this season as seventh in the league; the club has not won prizes for many years. Sporting remains a big club of course, but especially because of its history.
"Norwich is a small club compared to Sporting, but also a friendly club with a beautiful stadium and good fans. That suits me.
"The manager said I will be his number one striker. I know have to battle for it, but it's always good to get the confidence."