Pole barns are post and frame buildings typically built to be garages, riding rings or arenas, horse and hay barns or family homes. The flooring options are many and chiefly determined by the intended use of the pole barn, aesthetic concerns and your budget.
A soil or compressed dirt floor, possibly covered with periodically refreshed layers of hay is the most basic barn flooring option.
A concrete pad is a higher end but low maintenance and versatile pole barn floor. The concrete floor can be used raw, can be covered with hay and also with rubber matting. If the pole barn is used as a home this is a great under-layment for other surface flooring such as carpet or wood flooring. If using your pole barn as a garage, concrete is also a great easy-to-maintain option.
Fine aggregate and quik-crete can be compressed and lightly misted directly onto a dirt floor providing a semi-durable flooring that can keep minimize mud without the capital outlay of pouring a concrete pad.
A wood floor can be laid on a low joist structure and can be sheathed in plywood or OSB at the low end of the cost spectrum to tongue and groove hardwood on the high end.
The flooring options range from a few cents per square foot for a dirt or soil floor on the low end, to $2.00 a square foot for a compressed aggregate and quickcrete to $15 per square foot for hardwood. Depending on your use of the pole barn a sweep layer of hay may be a desirable added feature and that will have a nominal ongoing cost.