Frustratingly the linked article doesn't seem to actually *provide* the new formula. I recently read an article in the newspaper that may have been referencing this new formula, which was the natural log of the dog's age in years multiplied by 16, plus 31.

(ln[age in years]*16)+31

Example, using Dundee, 10, this comes out to be 67.8. Harsh, but probably fair.

You will note that the scale basically starts at 31. This reflects that unlike a 7 year old human, a dog even less than one can whelp. So the age curve is very steep at first; as the dog gets older the effect of the formula year-on-year is less.

This particular formula does not seem to factor in size.