Charlize Theron is ''so happy'' to be turning 40.

The 'Mad Max: Fury Road' actress will celebrate her birthday next month and revealed she's excited to hit the milestone because she's convinced people in their 40s are much better at enjoying life than youngsters.

She said: ''I'm so happy to be in my 40s and not be in my 20s and worried if I fit into my skinny jeans or whether I will be able to get into that club.

''It's so nice to just be in love with your couch and make cheesy sandwiches and just enjoy life. It's been great.''

The 39-year-old star - who split up with actor Sean Penn last month after over a year of dating - continued to say she is particularly looking forward to digging into a pile of cheese-filled snacks to mark her birthday.

She joked: ''Who doesn't love a cheesy sandwich? You just gotta go with good ol' gouda. Just good ol' gouda and good bread.''

But Charlize's positive outlook is nothing new as she has always been focused on staying upbeat and decided at the beginning of her acting career not to sacrifice herself to method acting because she didn't want to be ''tortured''.

Speaking to E! Online she said: ''I made a choice very early in my career that if my job was going to torture me, I love my life way too much to do that to myself. So I had to figure out a way to do it where I wasn't tortured.''