The balance is computed from
A = P(1 +r/n)^(nt)
where P is the principal, r is the annual interest rate, n is the number of times per year interest is compounded, and t is the number of years.
A = 1000(1 +.03/12)^(12*25) ≈ 2115.02
The account balance after 25 years will be $2,115.02.