@ErikaS, I have taken both Clonazepam and Diazepam. In my experience, 1 mg of Clonazepam feels similar to 10 mg of Diazepam. However, there's no way it's equal to 20 mg of Diazepam, as 20 mg would knock me out.
This conversion chart lists 1 mg of Lorazepam as equivalent to 0.5 mg of Clonazepam...