Will a yard of topsoil fit in 6 ft bed of pickup?

Yes. 1 Yard of topsoil will fit in a pickup bed of a truck BUT!!! it is heavy. So you will want to make sure the truck is rated for heavier weights. Probably something like a Ford Ranger or Chevy S-10 would be a little too small for a full yard of topsoil.

A yard is basically a full tractor bucket scoop. So if you can get an idea of how much that will be then that should help. Keep in mind that not all tractor buckets are 1 yard. Some are half, and some are more than 1 yard.

Any regular fullsize pickup truck should hold 1 Yard of topsoil just fine (regardless of the bed size) as long as it isn't wet.