For Continuous Compounding:
A=Pe^(rt)
where:
P = principal amount (initial investment)
e= Napier's Number ~ 2.7183 (if you have a scientific calculator, it should have it.
r = annual interest rate (as a decimal)
t = number of years
A = amount after time t
In your case t=1 month = 1/12 = 0.08333
The Compound Interest Equation
P = C (1 + r/n) nt
where
P = future value
C = initial deposit
r = interest rate (expressed as a fraction: eg. 0.06)
n = # of times per year interest in compounded
t = number of years invested
Even more
Here.