Android and setting width and height programmatically in dp units
Looking at your requirement, there is alternate solution as well. It seems you know the dimensions in dp at compile time, so you can add a dimen entry in the resources. Then you can query the dimen entry and it will be automatically converted to pixels in this call:
final float inPixels= mActivity.getResources().getDimension(R.dimen.dimen_entry_in_dp);
And your dimens.xml will have:
<dimen name="dimen_entry_in_dp">72dp</dimen>
Extending this idea, you can simply store the value of 1dp or 1sp as a dimen entry and query the value and use it as a multiplier. Using this approach you will insulate the code from the math stuff and rely on the library to perform the calculations.