A new Microsoft tool can allegedly predict how old you are based on a photo of you. We tested it out with a few celebrities and the results are pretty entertaining – for some it provides a bit of an ego boost but for others it’s demoralising. Find out who looked 91 years old and who only looked 38 years old.

If you want to find out how old you look, go to www.how-old.net and upload your photo for the results.

Tony Abbott – 57 years old

Dame Edna – 81 years old

Helen Mirren – 69 years old

Brad Pitt & Angelina Jolie – 51 and 39 years old

Paul Hogan – 75 years old

William & Kate – 32 and 33 years old

Image via RSVPMagazine

The Queen – 89 years old

Image via The Telegraph

Mick Jagger – 71 years old

Cliff Richard – 74 years old

Ronn Moss (Ridge Forrester) – 63 years old

Christie Brinkley – 61 years old

Keith Richards – 71 years old

Tell us, were you surprised, happy or disappointed with your results?