you mean steady state?... if steady state is the case..

That depends on your circuit parameters like

1. inductor

2. capacitor

3. input voltage

4. output voltage

it also depends on switching frequency.

I would say that the current in a buck converter looks like a saw tooth pattern; it rises with a constant rate until it reaches the critical magnitude where the ferrite material starts to go into saturation. You must avoid this saturation because it will heat up the windings and the transistor. In the saturation you can see that the current rises with a higher rate (almost vertical). Some circuits have limited duty-cycle for example 50% on-duty maximum possible. This is to ensure that the current does not reach the saturation point, and to ensure that there is sufficient time to send energy out of the magnetic field.

If you experience the saturation in your hardware setup, one solution can be to change the number of loops in the coil. For example from 7 to 8. This will reduce the rate of the rising current. A different solution is to choose a ferrite core which has a slightly larger air gap inside (I am thinking of the type called RM8 for example, which may have 0.17 or 0.10 mm air gap). The air gap makes a big difference and makes the reproducibility of your circuit better.

Hi

http://electronics.stackexchange.com/questions/32021/why-do-smaller-loads-require-larger-inductors-in-buck-regulators

http://www.onmyphd.com/?p=voltage.regulators.buck.step.down.converter

http://www.maximintegrated.com/en/app-notes/index.mvp/id/2031