Cheryl Cole ended her 30th birthday extravaganza in a tracksuit.

The 'Call My Name' singer swapped a designer dress for comfortable sportswear at a house party which ended her two-day celebration in the US, which is thought to have cost around £50,000.

A source told the Daily Mirror newspaper: ''It was an incredible weekend but the highlight was the Sunday house party. Everyone was dancing all afternoon. As it got to 10pm, Cheryl got changed. She was grinning ear-to-ear when the cake was brought out.''

Cheryl was joined by guests including her boyfriend Tre Holloway, her mother Joan Callaghan and her former Girls Aloud bandmates Nicola Roberts and Kimberley Walsh as they partied on Saturday night (29.06.13) at the Hakkasana club in Las Vegas, where her pal Calvin Harris was on the DJ decks, until 3.45am

The birthday girl and her crew then caught an early flight to Los Angeles, where they relaxed poolside at the mansion rented especially for the occasion.

Cheryl then slipped into her casual clothes to snack on barbecued meats and cake and was presented with gifts from her friends.

The insider added: ''But the best surprise was from Nicola and Kim - they read out a poem about Cheryl they wrote together. It was so funny - everyone was in stitches.''

The celebrations weren't over for Cheryl just yet, however, since her former 'X Factor' boss Simon Cowell purchased her the title of Lady by buying her some land in the Scottish Highlands to make up for missing her big bash.