Taylor Swift
Taylor Swift and Calvin Harris at BBMAs 2015 - the couple have been together for four monthsBillboard

They have only been dating for a matter of months but it looks like Calvin Harris has already decided that Taylor Swift is the woman for him. According to Life & Style magazine, the Scottish DJ is preparing to pop the question to the Bad Blood singer and is doing everything he can to make the moment unforgettable.

An insider claims that not only is he planning a big proposal, he is currently on the hunt for an impressive engagement ring. "Taylor loves chunky rings, so he wants to go big," the source told the magazine. "He's looking at cushion-cut centre stones and is willing to drop at least $500,000."

Although he already has his mind set on a particular rock, he is struggling to decide where he will pop the all-important question.

"He's on the fence because Taylor has so many favorite places," the source said. "He thought of romantic Paris or Italy, but now he's leaning toward Nashville, where she has one of her homes."

At least he does not have to worry about Swift saying "yes", because the 25-year-old pop superstar is allegedly ready to accept if he gets down on one knee.

The source added: "Even though they haven't been together that long, if he did ask her tomorrow she'd say yes, she's just so happy with him. Taylor doesn't think it's a sure thing, she's not that cocky, but she has a really good feeling that they will end up together."

News of the imminent proposal comes weeks after the power couple were named Forbes magazine's highest-paid celebrity couple of 2015. The lovebirds took the top spot with combined earnings of $146m (£92.8m) over the past 12 months – a staggering $35.5m more than reigning champions Beyonce Knowles and Jay Z.