Just Java™ 2

float

The type float refers to floating-point numbers stored in 32 bits, as described in the IEEE standard reference 754.

The justification for using single-precision variables used to be that arithmetic operations were twice as fast as on double precision variables. With modern extensively pipelined processors and wide data buses between the cache and CPUs, the speed differences are inconsequential. The reasons for using floats are to minimize storage requirements when you have a very large quantity of them or to retain compatibility with external data files.

Floats are best avoided if possible, because they have such limited accuracy. They are in Java because they are supported in hardware so it costs little, and provides compatibility ...