A New Jersey diner is tacking on an 18 percent gratuity on meals ordered by kids because it says youngsters don’t tip — a move that’s prompted a boycott by furious parents.

Mom Melissa Desch says that her 11-year-old daughter, along with the child’s pals at Schulyer-Colfax Middle School, are recent price gouge victims of the Wayne Hills Diner, a popular after-school hangout.

“My daughter looked down at her bill and realized that there is a charge for a tip, an 18 percent charge per child,” Desch told WABC in an interview.

Desch, who says she’s been going to the Wayne diner her entire life and never was automatically tip charged before, believes the youngsters are being targeted “because they’re kids and they don’t know any better.”

The bottom of her daughter’s receipts asks diners to leave a gratuity even though the tip was already added, Desch told the network.

“Even adults don’t always tip and it’s not anything against the servers, but you can’t assume that these kids don’t know what they’re doing,” said Desch, who claims she personally spoke to owner of the diner about the issue.

Desch said the owner told her the added tip is “policy because the kids run out and he feels that they don’t tip well, and they don’t know how to tip was the explanation.”

A manager at the diner confirmed to The Post an 18 percent tip is added to the pre-teen’s bills — because they simply don’t tip.

“We have kids coming in here every Friday, 20 to 25 at a time,” the manager said. “The kids don’t leave no tip.”

He said the diner adds the gratuity “because my employees need to get paid. They don’t work for free.”

The manager noted that most kids don’t tip at all, or some leave as little as 10 cents.

“We love the kids. They’ve been coming for years. We’re a family-owned business,” the manager said, adding the diner has lawyered up because of the hullabaloo, because, “there’s too much publicity for nothing.”

Menus at the diner read in fine print at the bottom: “management reserves the right to add 18 percent gratuity to check,” a photo of a menu shows.

Desch says she and other parents won’t patronize the joint anymore.

“There are enough parents that are willing to not let their kids go back there, and if it’s the same group she’s [her daughter] always hanging out with it could be 20, 30 kids,” Desch said. “I’m never going to go back, not after this.”