Global shoe sizes

What size is this? 28, 43, 10 and eleven and a half. Let's do the rounds. Japan, why 28? It's the length of the foot in centimetres. Oh, so a 28 centimetre foot wears a size 28. That is completely reasonable. We know France? Paris points. What's a Paris point? Two thirds of a centimetre. Why two thirds? No one knows. Possibly the length of a standard stitch back in the day. Hang on, 43 Paris points is 28.7 centimetres. But Japan says the foot's 28. Ah, we don't measure the foot, we measure the last. What's the last? The wooden foot the shoe's built around. Okay. UK, what do you use? Barleyscorns. Come again? A third of an inch. The length of one grain of barley. When was that decided? 1324, by Edward the Second. Really? That's the legend. Well, hang on. I wear a size 9, but 9 barleyscorns is only 3 inches. Ah, a size 9 is 34 barleyscorns. Then where does the 9 come from? Well, you start with size 0, which is 4 inches. And then go all the way up to 13. And then start again from one. You start again? The second count is adult sizes. Why not just keep counting after 13? 13 felt like enough. But again, 34 barleyscorns is 11 and a third inches, which is 29 cm. We also measure the last. US? Yep, also the last. What about your sizes? Please tell me you use one of these? Ish. The numbers are in approximation. They run a little bigger. Bigger by how much? Usually one size, but it depends on the brand. How can it depend on the brand? Each brand carves its own last. Also, each shoe has two sizes. That men's 10 is a women's eleven and a half. Is there any hope? There is an ISO standard. It's called MondoPoint. It's the length of the foot in millimetres. Yeah. Who uses it? Just ski boots? And several militaries. So the one system everyone agreed on is used for skiing and war? Correct. So if I walk into a shop and ask for a 28, you will be shown ski boots or enlisted.