Britney Spears showed off her new engagement ring last night at fiance Jason Trawick's 40th birthday party in Las Vegas.

The 3 carat, diamond paved band sparkler definitely cost a pretty penny, but how does it compare to other celebrities' engagement rings, and even her previous one?

Back in 2005, Kevin Federline bought Britney a 5.5 carat diamond engagement ring with platinum band. Both of her rings pale in size to other stars' rings.

Kris Humphries gave his soon-to-be ex-wife Kim Kardashian was a whopping 20.5 carat diamond ring valued around $2 million.

That tops the 20 carat ring Christina Aguilera received from ex-husband Jordan Bratman, the 18 carat ring Jay-Z gave to Beyonce, and the 17 carat ring Nick Cannon gave to Mariah Carey.

Reality stars don't fare too badly in the bling department. "Real Housewives" star Kim Zolciak received a 10 carat sparkler from Kroy Biermann. Kim's sister Khloe Kardashian was given a 9 karat, radiant-cut diamond paved band by Lamar Odom.

Check out all the photos of celebrity engagement rings, above!

Hot Videos