Michael Douglas' libido has finally "calmed down".

The 65-year-old actor - who has nine-year-old son Dylan and six-year-old daughter Carys with 40-year-old wife Catherine Zeta Jones - insists he is happier with himself than ever, but admits it can be difficult to relate to people of a similar age as his family situation is so different.

He told Esquire magazine: "I'm probably more comfortable with myself now, probably not leading with my libido quite as strongly, which comes with age and happiness.

"I've probably calmed down. It's interesting when you have kids at my age because you're kind of betwixt and between.

"Some of your friends, the only kids they've got are grandchildren."

The 'Wall Street: Money Never Sleeps' actor - who also has a 31-year-old son Cameron from his previous marriage - credits his union with Catherine, who he wed in November 2000, for helping him finally settle down.

He said: "I would say definitely around the time I married Catherine. I started making some conscious decisions and prioritising.

"As little children entered the equation - with a bride, an actress, 25 years younger, in her prime - the important part became them."

Michael also reveals he has experience with the stock market but unlike his 'Wall Street' character Gordon Gekko - famed for his motto "Greed is good" - his dalliance led him to lose millions of dollars.

He said: "I played. Years ago, through the tech booms. I definitely did it. I Lost 35 to 40 per cent of my net worth on the 2008 crash. At the end of last year, I took a whole bunch out."