Kourtney Kardashian. Picture: Instagram ( @kourtneykardash)

Kourtney Kardashian weighs 44.4kg, just 16.3kgs more than her eight-year-old son Mason.

The 38-year-old 'Keeping Up With the Kardashians' star revealed her and Scott Disick's eldest boy Mason tips the scales at 28kg, and she gained a pound.

During a conversation with their friend Simon Gebrelul, Kourtney's sister Khloe Kardashian was discussing her petite size after the raven-haired beauty had been for a jog. 

In a deleted scene from 'Keeping Up With the Kardashians', Khloe told Simon: "You know she's 97lbs?"

But Kourtney — who's 1.52 metres tall — , added: "Guess what? I gained a pound. I'm 98, since yesterday to today. You know Mason is 62?"

According to health experts, Kourtney's weight is inline with her body mass index. For a height of 1.52m, weight would vary from 41 to 57 kg, with an ideal weight of 50 kg.