(Cover) - EN Showbiz - Khlo Kardashian has been advising her sister Kim to "relax" if her wedding doesn't go to plan.

The reality TV star will wed basketball player Kris Humphries on August 20 after a whirlwind romance. Kim has previously admitted she's been dreaming of walking down the aisle for years and is frantically putting the finishing touches to plans at the moment.

Her sisters Khlo and Kourtney are her maids of honour and are trying to keep her nerves at bay as the big day approaches.

"If something goes wrong, just relax," Khlo advised. "Marriage is about you and your husband, not the flowers or the guest list."

Khlo is perfectly placed to help her sister plan the nuptials. She famously wed Lamar Odom in 2009 after dating for around a month.

She has been fully involved in all aspects of the upcoming nuptials, helping Kim pick her ten-tier wedding cake and Vera Wang dress and even giving ideas about music for the reception.

"Kim's so happy. Honestly, Kim is someone who has thought of her wedding from the day she was born," she laughed to the American edition of OK! magazine.

Ever since Kim announced her engagement rumours have swirled about the wedding. There was speculation there would be three ceremonies in different places, with the cost estimated at $20 million.

Khlo has laughed off that figure, insisting it couldn't be further from the truth. "Who in the world would EVER spend 20 mil on a wedding? Who would spend 20 mil on anything? LOL," she wrote on Twitter. "I doubt even [Bill Gates] would spend 20 mil on a wedding. LOL (sic)."

Kim added: "Haha I don't know where people come up w this stuff (sic)!" (C) Cover Media