concurring in part and dissenting in part.
I agree with the court that the trial judge properly awarded long-term alimony to Ka-thi. And I agree that the trial court should have performed the calculations and adjustments needed to reach a precise figure for Ken’s adjusted annual income. But its failure to do so does not require a remand of this case for further findings. Ken’s gross income exceeds $100,000 per year. Even after taking into account all arguably proper *202deductions, his adjusted gross income tops Rule 90.3’s income cap of $72,000. Because the trial court’s bottom line was correct, its failure to perform the necessary calculations is harmless. I would therefore affirm the child support obligation established by the superior court.
The superior court made a specific finding that Ken’s gross income exceeded $100,000 for 1996. This figure was comprised of “[t]o-tal gross earnings from the ferry system [of] $91,391.05; Permanent Fund dividend [of] $1,131; [and] commercial fishing income [of] $9,600,” totaling $102,122.05. The court identifies three deductions that the trial judge should have made to Ken’s gross income in determining Ken’s adjusted annual income for Rule 90.3 purposes: federal income taxes of $17,000; mandatory SBS of $3,843; and non-taxable per diem of $6,287. These adjustments total $27,298 and, when subtracted from Ken’s gross income, render an adjusted annual income of $74,824.05. Thus, if the majority were to give the appropriate level of deference to the trial court’s income findings, it could only conclude that the trial court’s conclusion that Ken’s adjusted annual income exceeded Rule 90.3’s $72,-000 cap was correct.
Yet the court chooses to question the trial judge’s finding regarding Ken’s fishing income because the trial judge “did not acknowledge the option” of averaging Ken’s fishing income over several years and “failed to mention” any fishing-related taxes or expenses in its findings.1 In so doing, the court ignores the fact that neither Rule 90.3 nor our case law compels income averaging. As the commentary to Rule 90.3 recognizes, income averaging is not required — it is merely a tool that the trial court “may choose” to employ when past income has been erratic.2 While the trial court has the choice of income averaging in such cases, it need not exercise this option nor need it make express findings when it elects not to do so. It was thus wholly appropriate for the trial court to rely on Ken’s 1996 fishing income in determining his adjusted annual income for that year.
Nor did the trial court miss any significant fishing expenses or taxes. Ken testified that his only fishing expenses for 1996 were $400-$500 in “actual out-of-pocket outlays” including his “share of fuel and groceries, clothes, a share of the gear that was lost, hooks and ganions.” And there was no testimony or argument at trial about the “fishing taxes” that apparently concern the court.3 Thus, the trial court’s failure to address fishing expenses was at most a $500 error, resulting in a 1996 fishing income of $9,100. Indeed, Ken’s lawyer conceded at trial that Ken’s fishing income for 1996, after out-of-pocket expenses, “was approximately $9000 net.” (Emphasis supplied.) Thus, even if the trial court neglected to consider fishing-related expenses, this would not affect the conclusion that Ken’s adjusted annual income exceeded $72,000.
In sum, I do not believe that a remand is necessary in this case. The superior court did not err in its findings on Ken’s gross income for 1996, and after the appropriate adjustments to that gross income figure are made, Ken’s adjusted annual income still exceeds Rule 90.3’s $72,000 income cap. Thus, the trial court’s failure to perform all necessary calculations in determining child support was harmless. For this reason, I respectfully dissent.
. Op. at 200.
. Alaska R. Civ. P. 90.3 Commentary III.E.
. Op. at 200.