Second, it is easier to make a mixture from common sense and then calculate the C:N ratio then to set out to get a specific C:N from several components. If you have 2 components and you know the moisture content, %N, and %C, one option is to start with asking what would the C:N ratio be if I started with 100 lbs of each? The %C and %N are based on what is present in dry material. So the first step is to estimate the weight of the dry material. The next step is to multiply the dry material time the %N and %C to get the pounds of N and C.