Depends on where you and those 15 acres are located.
15 acres = 653,400ft²
15 acres = 60,702.85 square meters
15 acres is 653,400 square feet
.15 acres
15 square miles = 9,600 acres.
15 acres
0.15 acres = 6,534 square feet
15 acres = 60702.85 sq metres (to 2 dp)
There are a lot of variables to consider here. Location, climate, vegetation, soil type/quality, forage biomass, and forage quality, whether you are using the land for grazing only or for hay and grazing that means raising your cattle for 365 days a year on only 25 acres are important factors that will determine how many cows you can feed on 25 acres. Some areas, like in the Southwest of the USA, you may be lucky to be able to feed 2 to 3 cows on 25 acres. Further north, like in the Northeast, you may be able to feed 15 to 25 cows on 25 acres. However, as mentioned above, this depends on whether you're just using these acres for grazing only, or if you are keeping your animals all year round and need it for hay production as well if you do not wish to buy hay.
72,600 square yards = 15 acres.
15 square miles = 9,600 acres.
150 acres is 15/64ths of a square mile.