Ask Excel: How old is my dog?

I thought my dog was only 14 in ‘dog years’ in biological terms. I was wrong! Excel showed me, in fact, that her true ‘dog age’ is actually very different.

What age is your dog? We all know the old story that a year of our life is like 7 years for a dog? Based upon the simple maths that we live on average 80yrs and a dog 12yrs so roughly a ratio of 7:1. But the reality is as usual, more complex than that. In fact, dogs age very quickly during their first couple of years and then level off substantially.

A team of researchers at the University of California, San Diego measured how the genes of labradors changed over time in ways that are associated with ‘ageing’ and found a rather surprising conclusion. (source)The relationship between ageing in dogs and humans is actually a logarithmic curve.

I decided to put this formula into an Excel workbook just for fun. Taking the human age from column cell (A2):

Age of dog calculator
The function to use is: dog age= 16*ln(human age)+31

We’re using the Excel function Ln which is a natural logarithm.

Now let us draw a graph of it.

Select both cells and drag them now a few rows..

Excel create chart

Right-click on one of the tables cells and select Quick Analysis

Excel create chart 2
Excel create chart 3

Select Charts tab and then line chart. You should get a chart something like this..

Suppose now you wanted to share this wonderful fact with all your colleagues? The best way is possibly by writing a simple web app that may work similarly to this one:


If you want to Ask Excel anything, please leave a comment on this post.