InterDigital, Inc.

Adjusted EBITDA and Adjusted EBITDA margin are supplementalnon-GAAP financial measures that InterDigital believes provide investors with important insight into the company’s ongoing business performance. InterDigital defines Adjusted EBITDA as net income attributable to InterDigital Inc. plus net loss attributable tonon-controlling interest, income tax (provision) benefit, other income (expense) & interest expense, depreciation and amortization, share-based compensation, and other items. Other items include restructuring costs, impairment charges and othernon-recurring items. Adjusted EBITDA margin is adjusted EBITDA over total revenues. Thesenon-GAAP financial measures may be calculated differently from, and therefore may not be comparable to, similarly titled measures used by other companies. A detailed reconciliation of adjusted EBITDA and adjusted EBITDA margin to the most directly comparable GAAP financial measure is provided below.

Pro Forma EBITDA is a supplementalnon-GAAP financial measure that InterDigital uses for compensation purposes as described in this proxy statement. InterDigital defines Pro Forma EBITDA as total revenues minus operating expenses plus depreciation and amortization, intellectual property enforcement costs, and other items. Other items include restructuring costs, impairment charges and othernon-recurring items, as further described below. Thisnon-GAAP financial measure may be calculated differently from, and therefore may not be comparable to, similarly titled measures used by other companies. A detailed reconciliation of Pro Forma EBITDA to the most directly comparable GAAP financial measure is provided below.

Non-GAAP net income, Non-GAAP diluted earnings per share, and Non-GAAP weighted-average diluted shares are supplementalnon-GAAP financial measures that InterDigital believes provides investors with important insight into the Company’s ongoing business performance. InterDigital defines Non-GAAP net income as net income attributable to InterDigital, Inc. plus share-based compensation, acquisition related amortization, depreciation and amortization, restructuring costs, impairment charges andone-time adjustments, losses on extinguishments of long-term debt, the related income tax effect of the preceding items, and adjustments to income taxes. Non-GAAP diluted earnings per share is defined as Non-GAAP net income divided by Non-GAAP weighted average diluted shares, which adjusts the weighted average number of common shares outstanding for the dilutive effect of the Company’s convertible notes, offset by our hedging arrangements. InterDigital’s computation of thesenon-GAAP financial measures might not be comparable to similarly named measures reported by other companies. The presentation of these financial measures, which are not prepared under any comprehensive set of accounting rules or principles, is not intended to be considered in isolation or as a substitute for the financial information prepared and presented in accordance with GAAP. A reconciliation of each of these metrics to its most directly comparable GAAP financial measure is provided below.