Forgot to post this last night

A post shared by Kim Kardashian West (@kimkardashian) on

Kim Kardashian has wowed her Instagram following by sharing a snap of herself in a black bikini, showing off months of hard work in the gym and her new 24 inch waist as a result.

The 37-year-old reality TV star sent some of her 107 million followers into a spin when she posted the glamorous snap of herself in the high-rise skimpy two piece, which she accessorised with a chunky diamante choker necklace and a heavy makeup look of grey smoky eyes and nude lips.

The mother-of-three, who welcomed baby daughter Chicago with husband Kanye West via surrogate in January, also sported her recent peroxide blonde hairdo in a bob cut.

She captioned the shot: "Forgot to post this last night," which was met with a slew of comments from her fans.

One person said of her slimmed-down physique: "Good on you!! You look great and work hard! X," while someone else said: "SLAYINGGG ."

A third added: "Superb figure."

Others didn't quite agree, with another writing: "U are a mother u shouldn't act like this on social media I can not imagine what another parents and especially ur children will think of their mother when they'll grow up."

The reality star is hell-bent on sharing snaps of her new 24-inch waist, which she has obtained by regular workouts and a high protein diet.

Kardashian discussed having a 24-inch waist in a video from her book club posted to her app, telling her fans: "It's never been 24 ever in my life."

While her fellow fitness fanatic sister Kourtney, 38, told her: "I can't take your hips seriously right now. Because your waist is so small and your hips are so big."

The reality star worked incredibly hard to drop the 70lbs she gained during her two pregnancies with North and Saint, beginning the Atkins diet once again in December 2015. She also became more committed and serious about her fitness regime, training nearly every day with fitness expert Melissa Alcantara.

Alcantara told People at the end of last year: "[Kim] just wanted more muscle. She wanted bigger hamstrings, which accentuates the entire leg. And she wants those cut arms and abs!"

kim kardashian
Kim Kardashian West attends the 2017 LACMA Art Film Gala Honoring Mark Bradford and George Lucas presented by Gucci at LACMA on November 4, 2017 in Los Angeles, California Getty