Jake Gyllenhaal bought Taylor Swift a $100,000 bracelet for her birthday.

The 30-year-old actor - who has been romantically linked to the singer since October - showered the 'Love Story' hitmaker with several thoughtful presents when she turned 21 on December 13, and even took the time to make her a personalised card.

A source told In Touch Weekly magazine: "It's an Oscar-worthy bracelet - nearly 30 carats of colourless diamonds set in white gold. It cost Jake about $100,000, but he wanted to do something special for Taylor's birthday.

"They love coffee, so he sent her 21 pounds of the best Kona coffee available, along with a coffee grinder and a coffeemaker. And he made her a birthday card, as opposed to buying a generic one!"

As well as Jake's efforts to please Taylor, the singer is also doing her best to make the actor happy, with her friends claiming she has even changed her style to suit her boyfriend's tastes.

One insider explained: "She's decided to get a more sophisticated look. She's buying from stores like Chanel, Prada and Hermes."

As well as the bracelet and the coffee, it has also been claimed that Jake paid $11,000 for a guitar signed by country music icon Chet Atkins for his girlfriend.

A source said: "He spent the weekend in Nashville with her and she saw the guitar in a tiny store which a lot of A-list musicians use.

"He was originally going to buy it just as a gift but it ended up being perfect for her birthday."