The JavaFX font APIs take a size parameter which is described as being in "points" (units of 1/72 inch):

     * @param size The point size of the font. This can be a fractional value,
     * but must not be negative. If the size is < 0 the default size will be
     * used.

In fact the size is a measure of pixels, not points. The documentation should be updated to reflect this.