Archant says the weekly pro-European Union paper, set up after last June’s referendum, will also increase its pagination from 48 to 64 and publish a day earlier, on Thursdays.
The move will take effect from 13 July, five days after the anniversary of its first edition.
The price of the paper, which was initially scheduled to run for just four issues, will stay the same across the UK and Europe.
Editor Matt Kelly said: “We’ve asked our subscribers and they’ve told us it’s not the size of the paper that matters but the fresh alternative to old established media.
“The New European will be smaller in size, bigger in pages and every bit as brilliant as it is today.
“Plus, you won’t be knocking elbows with people on the bus or train when you read it.”
The New European is currently printed in Berliner format by Guardian-owned presses, and comes after The Guardian also announced it would be switching to tabloid.