According to regulation size specifications, the answer to how many acres a baseball field is is that a baseball field should measure approximately 400 feet by 400 feet. This is an area of about three acres.
For some in-depth information of the construction, layout and sizing of a baseball field, visit the Baseball Almanac. This site includes helpful reminders about keeping your playing field level, allowing for water drainage, having equipment (like bases) and maintaining your turf.
The key to building a good baseball field is to make sure that you don’t take any shortcuts, and you allot enough time, effort, and resources to build the field to these regulation specifications.
Since a baseball field will last many years, it is important to make sure that it is sized correctly, as you will no doubt regret taking shortcuts when the end result could be a sub standard field. Irregularly sized playing fields can be a source of frustration compared to a real field built to the proper size specifications. It is important to build the field to the proper size so that games do not result in having a lot of foul balls or home runs that are impossible to field because the size of the field is too small (or even to big) to allow for proper game play.
Three acres is not a lot of land to devote to a field that can generate a lot of revenue and enjoyment for everyone who plays there.