I grew tired of having to convert my units just for the sake of specifying the figure size. I'd like to specify the figure size directly in a metric unit, nominally centimeters (or millimeters, no difference). In most EU countries metric is the norm. I only have to deal with inches when looking at monitor sizes, printing, and matplotlib :(

I've found at least two issues about this: #1369 and the more generic #9226.

Of course, having support for generic unit specifiers would be nice, but I'm not entirely satisfied by the extra complexity of #9226. I'm also thorn about (size, unit) tuples, because I don't ever think I'm going to specify the figure size in AU, or picometers. Cm is regularly used for anything that fits paper.

I see two cases where inches are specified in the rc:

• figure.figsize
• savefig.pad_inches

In the api, there is the figsize kwarg, I guess a pad_inches kwarg, and the set_size_inches method.

What abound the KISS approach: add a figsize_cm kwarg, pad_cm, and the set_size_cm method, and the two respective rcParams? Fully backward compatible, and allows metric countries to get by easily.

I could easily contribute such a patch.