Caitlyn Jenner reportedly spent $4 million on her gender transformation.

Caitlyn Jenner's daughters Kylie and Kendall Jenner

Caitlyn Jenner's daughters Kylie and Kendall Jenner

The 65-year-old former Olympian - who was previously known as Bruce Jenner - is believed to have splashed out the hefty sum on cosmetic surgery and having her closet remodelled.

A plastic surgeon estimated that her cosmetic surgery could have cost $81,000, with over $10,000 being spent on her breast enhancement in April, reports Radar Online.

The bustier which Caitlyn wore for the Vanity Fair magazine shoot, her first photo shoot as a woman, cost $200 with another gown costing a pricey $7,000.

Her closet, which cost $15,000 to be remodelled, is believed to be full of brand new dresses worth approximately $150,000.

Since undergoing her gender transition, Caitlyn revealed she has finally been able to throw out the boys clothes in her wardrobe.

She said: "To be able to wake up in the morning, be yourself, get dressed, get ready to go out, and just be like a normal person. That's a wonderful feeling to go through life.

"I've never been able to do that; it's always been confusion, it's always been, you know, I've got one side [with] boy clothes, the other side's women's clothes. It's like I cleaned the whole closet out - the boys stuff is gone, okay?"