Kate Hudson says she ''deserves a hangover'' after giving birth to her third child last year.

The 'Almost Famous' actress is set to celebrate her 40th birthday later this month, and has said that since becoming a mother of three - to children Ryder, 14, Bingham, seven, and Rani Rose, six months - she feels like she's earned a night of partying that will leave her with a ''really good hangover'' the following morning.

Asked how she plans to spend her birthday, she said: ''At this point, I just want to tell everybody, 'Hey, I'm gonna have a party,' and then everybody shows up.

''I personally, with having a baby, feel like I deserve a really good hangover. I've been so good, I've been so busy. I've been breastfeeding like crazy and I just want some martinis. I want to sleep in. [That'd be] really nice.''

But despite wanting to unwind from the pressures of motherhood, Kate says she almost cries ''every day'' from watching her two sons dote on their little sister, who is her first child with boyfriend Danny Fujikawa.

She added: ''Seeing the boys with her ... I feel like I tear up every day. To see [Ryder] with his sister and to be a real helper and for me to be able to walk away and go, 'Hey, honey, can you just take the baby?' And I turn around and I'm like, 'Oh, my gosh.'''

And the 'Bride Wars' star says her family are ''so happy'', as although there's a level of chaos at home, the ''energy is calm and loving''.

Speaking on 'Good Morning America', Kate said: ''I've been having babies a long time, let's put it that way. But it's good. Everyone's so happy and I feel, right now ... even though it's chaotic, the energy is calm and loving and peaceful right now and I'm just in a great place.''