described above and excludes an estimated $18 million in stock-based compensation expense, $4 million in acquisition and litigation-related costs, $62 million of amortization expense of acquired intangible assets, and includes $1 million of amortization expense for GoTo’s internally capitalized software development costs that were adjusted in acquisition accounting to fair value, as well as the income tax effect of the above items.
Non-GAAP net income for the fourth quarter assumes an effective tax rate of approximately 25% and GAAP net income assumes a tax provision of $8 million for the fourth quarter.Non-GAAP and GAAP net income per diluted share is based on an estimated 51.7 million fully-diluted weighted average shares outstanding.
Including stock-based compensation expense, acquisition-related costs and amortization, litigation-related expense, and excluding the acquisition accounting adjustments to revenue and amortization expense, the Company expects to report GAAP net income in the range of $5 million to $6 million, or $0.10 to $0.11 per diluted share.
Fiscal year 2018: The Company expects full year 2018non-GAAP revenue to be in the range of $1.203 billion to $1.204 billion. The Company expects full year 2018 GAAP revenue to be in the range of $1.199 billion to $1.200 billion.Non-GAAP revenue adds back $4 million for the impact of an acquisition accounting adjustment recorded to reduce acquired deferred revenue to the fair value of the remaining obligation.
EBITDA is expected to be in the range of $382 million to $383 million, or approximately 32% of GAAP revenue. Adjusted EBITDA is expected to be in the range of $442 million to $443 million, or approximately 37% ofnon-GAAP revenue.
Non-GAAP net income is expected to be in the range of $280 million to $281 million, or $5.33 to $5.34 per diluted share.Non-GAAP net income adds back thenon-GAAP revenue adjustment described above and excludes an estimated $67 million in stock-based compensation expense, $23 million in acquisition and litigation-related costs, $245 million of amortization expense of acquired intangible assets, a $34 millionpre-tax gain associated with the disposition of anon-core asset and includes $8 million of amortization expense for GoTo’s internally capitalized software development costs that were adjusted in acquisition accounting to fair value, as well as the income tax effect of the above items and discrete tax items.
Non-GAAP net income for the fiscal year assumes an effective tax rate of approximately 25% and GAAP net income for the fiscal year assumes an effective tax rate of approximately 29%.Non-GAAP and GAAP net income per diluted share is based on an estimated 52.5 million fully-diluted weighted average shares outstanding.
Including stock-based compensation expense, acquisition-related costs and amortization, litigation-related expense, and excluding the acquisition accounting adjustments to revenue and amortization expense, the Company expects to report GAAP net income in the range of $54 million to $55 million, or $1.03 to $1.04 per diluted share.