"Sorry the farm can't hold that large of a plot"

There seems to be a bug determining whether a plot is too large. In the below screenshot, the farm has 12.96 squares unplanted, but attempting to start a 12.96-square plot produces the "Sorry the farm can't hold that large of a plot" error. At first glance, this seems like a simple case of using < instead of <=, however, if the 1-square parsley plot is deleted, the 12.96-square basil plot can be created (leaving 1 square free), and the 1-square parsley plot can be recreated. So it seems like the more likely culprit is a rounding error due to accidentally using binary floating-point rather than decimals for the calculations.