Chilton, 21, graduates from GP2 and joins Marussia, becoming the fourth Brit on the 2013 grid.
Chilton joined the team as reserve driver ahead of the Singapore Grand Prix and also drove for Marussia in the young driver test and in practice in Abu Dhabi.
"I wouldn't have wanted to make the step up if I wasn't ready," he told Sky Sports News.
"I believe after my last year in GP2 with two wins and two pole positions I am ready and when I got behind the wheel in Abu Dhabi for practice I felt comfortable and that is the main thing - I know I can do it."
Chilton acknowledges that Marussia is in for a tough season, but believes that testing will be crucial to determining 2013 targets.
"After three long, hard seasons in F1 the team are yet to score a point and if I can score their first points then that will be an incredible feeling. Hopefully if testing goes well we can get that done early on in the season and then I can change my targets as we go".
Marussia has yet to confirm a replacement for Timo Glock or a launch date for their 2013 challenger.