Bruce Willis can change his baby's nappy in under seven seconds.

The Hollywood tough guy has a 10-month-old daughter, Mabel, with his wife Emma Heming-Willis and when it comes to dealing with poop he is the quickest in the house.

He said: ''I hold the record for speed changing - I'm under seven seconds.''

The 57-year-old actor - who also has daughters Rumer, 24, Scout, 21, and Tallulah, 19, with ex-wife Demi Moore - admits having a child again later in his life has been a great experience because he can devote more time to Mabel because he's had such a successful career.

In an interview with the USA Today newspaper, he said: ''(My focus) is like how can I make this child laugh today. I act out all of my parts. And the goofier I do, the better ... It's all I want to do. Acting is so far down the road as compared to any time hanging out with my kids.''

Bruce has reprised his role as John McClane for a fifth time in 'A Good Day To Die Hard' and in January Fox Studio executives unveiled a 50ft mural of the character at Stage 8 of the movie lot in tribute to the franchise.

The screen star admits his grown-up kids mocked him because the depiction of his character has hair and bright blue, something they claim they haven't seen their dad with for a long time.

Bruce - who has been bald for several years - laughed: ''They were cracking up, saying that my eyes are not blue. And they don't remember me with hair. And they were saying, 'You're making that up, right, about the billion dollars?' But they were very nice about it.''