The actress - whose birthday is in April - says there's an "influx of subliminal messaging" around about what you should have achieved by that age.

"If you do not have a husband, if you do not have a baby… There's just this incredible amount of anxiety," she told British Vogue.

But Emma adds that she's happy single, calling it "being self-partnered".

The Harry Potter actress says previously she'd never believed the idea that you could be happy and be single.

"I was like, 'This is totally spiel'. It took me a long time, but I'm very happy [being single]."

Emma first spoke about feminism at the UN in 2014

Emma, who's also an activist and campaigns for women's rights, says the past year has been "tough" because of the stage of life she's at.

"I was like, 'Why does everyone make such a big fuss about turning 30? This is not a big deal'.

"Cut to 29, and I'm like, 'Oh my God, I feel so stressed and anxious.

"And I realise it's because there is suddenly this influx of subliminal messaging around.

"If you have not built a home, if you do not have a husband, if you do not have a baby, and you are turning 30, and you're not in some incredibly secure, stable place in your career, or you're still figuring things out…There's just this incredible amount of anxiety."

Emma met French President Emmanuel Macron earlier this year for a discussion about gender equality

Emma stars in the upcoming film adaptation of Little Women, alongside Timothee Chalamet, Saoirse Ronan and Florence Pugh.

But it was working with co-stars Laura Dern and Meryl Streep which she says she really enjoyed.

"The three of us knew each other way before we did Little Women," she told British Vogue for its December issue.

"We met in activist spaces, so we had this allyship and solidarity as activists that had been part of a certain movement before we ever worked together."

Laura Dern and Meryl Streep also star in Greta Gerwig's Little Women

Emma Watson is a UN Women goodwill ambassador and was also part of the launch of the campaign He For She - which fights for gender equality around the world.

As part of that, she interviewed Nobel peace prize winner Malala Yousafzai.

Malala has said that Emma was the reason she identified as a feminist and was no longer doubtful about using the label for herself.