How browsers position floats

When you have a float CSS property on a box (with a value different than none), this box must be laid out according to the float positioning algorithm. Loosely, it says:

Anyway, in general you’ll have a better time if you use a flexbox or CSS grid instead of floats, because floats are quirky and have strange edge cases, but if you were ever curious about how the algorithm would choose where to position different floats, here’s a demo (which you can also play with directly on glitch):