Analysis from:
Here are the applicable guidelines.
The guideline for Obstruction of Justice is here. The base level is 14, but 3 points can be added "If the offense resulted in substantial interference with the administration of justice."
The Perjury guideline is here. It also is a level 14 but "If the perjury, subornation of perjury, or witness bribery resulted in substantial interference with the administration of justice, increase by 3 levels."
"Substantial interference with the administration of justice" includes a premature or improper termination of a felony investigation; an indictment, verdict, or any judicial determination based upon perjury, false testimony, or other false evidence; or the unnecessary expenditure of substantial governmental or court resources.
The False Statement guideline is here.
The guideline enhancement for Abuse of Special Trust, which may or may not apply, is here.
If the defendant abused a position of public or private trust, or used a special skill, in a manner that significantly facilitated the commission or concealment of the offense, increase by 2 levels.
After calculating the guidelines for each offense, the grouping rules have to be considered because he was convicted of more than one count.
There are also various downward departures, but I don't see any of those being applicable. Nor do I see Libby getting any credit for "acceptance of responsibility."
After the final offense level is computed, it's cross-referenced with criminal history category, which if Libby has no prior convictions, will be I. Then you go to this chart and find the sentencing range.
My preliminary estimate: I think the lowest his guidelines will be is the 15 to 21 month range and the highest would be the 24 to 33 month range.
Because he was a high level government official and a lawyer who obstructed justice, I would expect the judge to sentence him towards the high end of the applicable sentencing range, particularly if enhancements aren't applied.