23 Definition of Non-GAAP Financial Measures This presentation includes certain non-GAAP financial measures that management believes are helpful in understanding our business, as further described below. Our definition and calculation of non-GAAP financial measures may differ from those of other REITs, and, therefore, may not be comparable. The non-GAAP financial measures should not be considered an alternative to net income or any other GAAP measurement of performance and should not be considered an alternative to cash flows from operating, investing or financing activities as a measure of liquidity. Funds from Operations (FFO) We calculate Funds from Operations, or FFO, in accordance with the standards established by the National Association of Real Estate Investment Trusts, or NAREIT. FFO represents net income (loss) (computed in accordance with GAAP), excluding gains (or losses) from sales of property, real estate related depreciation and amortization (excluding amortization of deferred financing costs) and after adjustments for unconsolidated partnerships and joint ventures. Management uses FFO as a supplemental performance measure because, in excluding real estate related depreciation and amortization and gains and losses from property dispositions, it provides a performance measure that, when compared year over year, captures trends in occupancy rates, rental rates and operating costs. We also believe that, as a widely recognized measure of the performance of REITs, FFO will be used by investors as a basis to compare our operating performance with that of other REITs. However, because FFO excludes depreciation and amortization and captures neither the changes in the value of our properties that result from use or market conditions, nor the level of capital expenditures and leasing commissions necessary to maintain the operating performance of our properties, all of which have real economic effect and could materially impact our results from operations, the utility of FFO as a measure of our performance is limited. Other REITs may not calculate FFO in accordance with the NAREIT definition and, accordingly, our FFO may not be comparable to such other REITs’ FFO. Accordingly, FFO should be considered only as a supplement to net income as a measure of our performance. EBITDA and Adjusted EBITDA We believe that earnings before interest, income taxes, depreciation and amortization, or EBITDA and Adjusted EBITDA (as defined below), are useful supplemental performance measures because they allow investors to view our performance without the impact of noncash depreciation and amortization or the cost of debt and with respect to Adjusted EBITDA preferred dividends and minority interests. Adjusted EBITDA is EBITDA excluding minority interests and preferred stock dividends. In addition, we believe EBITDA and adjusted EBITDA are frequently used by securities analysts, investors and other interested parties in the evaluation of REITs. Because EBITDA and adjusted EBITDA are calculated before recurring cash charges including interest expense and income taxes, and are not adjusted for capital expenditures or other recurring cash requirements of our business, their utility as a measure of our performance is limited. Accordingly, EBITDA and Adjusted EBITDA should be considered only as supplements to net income (computed in accordance with GAAP) as a measure of our financial performance. Other equity REITs may calculate EBITDA and Adjusted EBITDA differently than we do; accordingly, our EBITDA and Adjusted EBITDA may not comparable to such other REITs’ EBITDA and Adjusted EBITDA. Each of FFO and Adjusted EBITDA exclude items that have real economic effect and could materially impact our results from operations, and therefore the utility of FFO and Adjusted EBTIDA as a measure of our performance is limited. Nothing contained herein is intended to revise the earnings, FFO or acquisition guidance we confirmed on our Earnings Conference Call dated March 2, 2006 and available on our website at www.digitalrealtytrust.com. | 
