The 'All Time Low' group made the claim as they were added to the bill of this year's iTunes Festival. The band play a free show at the London Roundhouse in July and tickets are available via a prize draw on the event's website.
Singer Siva Kaneswaran said: "We want to be as big or bigger than Take That."
Of fellow boyband McFly, he added: "McFly have much better bodies than us. If it was for a good cause we'd strip again. But McFly take the trophy. We can't can't compete with them."
Regarding their upcoming iTunes show, Kaneswaran said: "We went and watched last year so this is wicked. We're going to be doing something really special. We just do our thing and, hopefully, people will enjoy it. I think we've got our own style."
Other artists confirmed for this year's festival include Beady Eye, Duran Duran and Adele.