The Scottish DJ, who started dating the 'Blank Space' hitmaker in March after they were set up by mutual friend Ellie Goulding, is said be preparing to get down on bended knee with a $1.4m engagement ring by the end of October.
A source close to the 31-year-old star, who was spotted shopping for jewellery at XIV Karats in Beverly Hills earlier this month, said: "He said he wanted something 'very special' for Taylor. He was asking about the best cuts and eyed a ring that was $1.4m! He was clearly eager to get the perfect rock, no matter the cost."
While they haven't been dating for very long, the 25-year-old singer's pals believe she's also ready to take the next step with her beau.
An insider told the US edition of OK! magazine: "She's not shy about telling anyone who'll listen that she loves him, and she's not being coy around him either. At a recent dinner, she blurted it out and asked if he'd ever consider marrying her!"
The couple haven't been spotted together in recent weeks, but are in constant contact while Taylor continues the North American leg of her '1989 World Tour'.
Another source told HollywoodLife.com: "Taylor and Calvin have been super busy with their schedules so they haven't been able to spend much time together physically. But they still talk and text every day. They have a sexy Skype session whenever they can to keep their relationship exciting."