# Population Pyramid

Andrew Lang

The population pyramid is a chart type suited to showing the relative populations of two different categories over a time dimension, as the name suggests its most commonly employed for showing the variation of age within a population.

Image from census.gov; https://goo.gl/RzsjqF

To accomplish this we can use one simple calculation to create a diverging scale:

Here when the row is referring to men we invert the value when we then create the graph broken down by male and female, men should fall to the left of the zero line and women to the right of the line;

The next step is to do some formatting first, we sort the age scale so that it runs from low to high. We can also change the formatting of the population axis to make the negative values look like positive ones.

Giving us our final result:

If you want to dissect the chart or explore the data I have used you can download the workbook from tableau public here: https://goo.gl/kBY8NX

As always if there are any questions feel free to leave them in the comments below.