Exhibit 99.4

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

The Unaudited Pro Forma Condensed Combined Financial Statements (referred to as the “pro forma financial statements”) have been derived from the historical consolidated financial statements of Great Plains Energy Incorporated (“Great Plains Energy”) and Westar Energy, Inc. (“Westar”). The pro forma financial statements should be read in conjunction with the:

The pro forma financial statements give effect to the merger, Great Plains Energy’s expected equity and debt issuances to finance the cash portion of the merger consideration and the redemption by Great Plains Energy of all of its existing outstanding preferred stock (collectively referred to in this section as the “transactions”). Great Plains Energy has obtained committed financing in the form of a $7.517 billion senior unsecured bridge term loan facility from Goldman Sachs Bank USA and Goldman Sachs Lending Partners LLC. However, Great Plains Energy has prepared its pro forma financial statements assuming the cash portion of the merger consideration will be financed through its expected issuances of equity and debt based on current market conditions, and as a result, these pro forma financial statements assume that Great Plains Energy will not borrow any amounts under the bridge term loan facility. Any borrowings under the bridge term loan facility would be classified as short-term debt in current liabilities.

The Unaudited Pro Forma Condensed Combined Statements of Income (referred to as the “pro forma statements of income”) for the six months ended June 30, 2016 and for the year ended December 31, 2015 give effect to the transactions as if they occurred on January 1, 2015. The Unaudited Pro Forma Condensed Combined Balance Sheet (referred to as the “pro forma balance sheet”) as of June 30, 2016 gives effect to the transactions as if they occurred on June 30, 2016.

The historical consolidated financial information has been adjusted in the pro forma financial statements to give effect to pro forma events that are: (1) directly attributable to the merger; (2) factually supportable; and (3) with respect to the statements of income, expected to have a continuing impact on the combined results of Great Plains Energy and Westar. As such, the impact from merger related expenses is not included in the accompanying pro forma statements of income. However, the impact of these expenses is reflected in the pro forma balance sheet as an increase to other current liabilities and a decrease to retained earnings.

As described in the accompanying notes, the pro forma financial statements have been prepared using the acquisition method of accounting under existing generally accepted accounting principles (“GAAP”), and the regulations of the Securities and Exchange Commission. Great Plains Energy has been treated as the acquirer in the merger for accounting purposes. The purchase price for the pro forma financial statements has been estimated based on (1) the number of outstanding shares of Westar common stock on June 30, 2016, and (2) an assumed exchange ratio of 0.2963 determined using the 20-day volume-weighted average price per share of Great Plains Energy common stock ending on August 1, 2016.

Assumptions and estimates underlying the pro forma adjustments are described in the accompanying notes, which should be read in connection with the pro forma financial statements. Since the pro forma financial statements have been prepared based on preliminary estimates, the final amounts recorded at the date of the merger may differ materially from the information presented. These estimates are subject to change pending further review of the assets acquired and liabilities assumed and the final purchase price.

The pro forma financial statements have been presented for illustrative purposes only and are not necessarily indicative of the results of operations and financial position that would have been achieved had the pro forma events taken place on the dates indicated, or the future consolidated results of operations or financial position of the combined company.

GREAT PLAINS ENERGY INCORPORATED

Unaudited Pro Forma Condensed Combined Balance Sheet

June 30, 2016

The accompanying Notes to the Unaudited Pro Forma Condensed Combined Financial Statements are an integral part of these statements.

GREAT PLAINS ENERGY INCORPORATED

Unaudited Pro Forma Condensed Combined Balance Sheet

June 30, 2016

The accompanying Notes to the Unaudited Pro Forma Condensed Combined Financial Statements are an integral part of these statements.

GREAT PLAINS ENERGY INCORPORATED

Unaudited Pro Forma Condensed Combined Statement of Income

For the Six Months Ended June 30, 2016

The accompanying Notes to the Unaudited Pro Forma Condensed Combined Financial Statements are an integral part of these statements.

GREAT PLAINS ENERGY INCORPORATED

Unaudited Pro Forma Condensed Combined Statement of Income

For the Year Ended December 31, 2015

The accompanying Notes to the Unaudited Pro Forma Condensed Combined Financial Statements are an integral part of these statements.

NOTES TO THE UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

Note 1. Basis of Pro Forma Presentation

The pro forma statements of income for the six months ended June 30, 2016 and for the year ended December 31, 2015 give effect to the transactions as if they were completed on January 1, 2015. The pro forma balance sheet as of June 30, 2016 gives effect to the transactions as if they were completed on June 30, 2016.

The pro forma financial statements have been derived from the historical consolidated financial statements of Great Plains Energy and Westar. Assumptions and estimates underlying the pro forma adjustments are described in these notes, which should be read in conjunction with the pro forma financial statements. Since the pro forma financial statements have been prepared based upon preliminary estimates, the final amounts recorded at the date of the merger may differ materially from the information presented. These estimates are subject to change pending further review of the assets acquired and liabilities assumed.

The merger is reflected in the pro forma financial statements as an acquisition of Westar by Great Plains Energy, based on the guidance provided by accounting standards for business combinations. Under these accounting standards, the total estimated purchase price is calculated as described in Note 2 to the pro forma financial statements, and the assets acquired and the liabilities assumed have been measured at estimated fair value. For the purpose of measuring the estimated fair value of the assets acquired and liabilities assumed, Great Plains Energy has applied the accounting guidance for fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. The fair value measurements utilize estimates based on key assumptions of the merger, including historical and current market data. The pro forma adjustments included herein are preliminary and will be revised at the time of the merger as additional information becomes available and as additional analyses are performed. The final purchase price allocation will be determined at the time that the merger is completed and the final amounts recorded for the merger may differ materially from the information presented.

Estimated transaction costs have been excluded from the pro forma statements of income as they reflect non-recurring charges directly related to the merger. However, the anticipated transaction costs are reflected in the pro forma balance sheet as an increase in other current liabilities and a decrease in retained earnings.

The pro forma financial statements do not reflect any cost savings (or associated costs to achieve such savings) from operating efficiencies that could result from the merger. Further, the pro forma financial statements do not reflect the effect of any regulatory actions that may impact the pro forma financial statements when the merger is completed.

Westar’s regulated operations are comprised of electric generation, transmission and distribution operations. These operations are subject to the rate-setting authority of the Federal Energy Regulatory Commission and the Kansas Corporation Commission and are accounted for pursuant to GAAP, including the accounting guidance for regulated operations. The rate-setting and cost recovery provisions currently in place for Westar’s regulated operations provide revenue derived from costs including a return on investment of assets and liabilities included in rate base. Thus, the fair values of Westar’s tangible and intangible assets and liabilities subject to these rate-setting provisions approximate their carrying values, and the pro forma financial statements do not reflect any net adjustments related to these amounts.

Note 2. Preliminary Purchase Price and Preliminary Purchase Price Allocation

The merger agreement provides that each outstanding share of Westar common stock at the effective time of the merger (subject to certain exceptions) will be converted into the right to receive $51 of cash consideration and a number of shares of Great Plains Energy common stock equal to an exchange ratio that may vary between 0.2709 and 0.3148, based upon the volume-weighted average share price of Great Plains Energy common stock on the New York Stock Exchange for the 20 consecutive full trading days ending on (and including) the third trading day immediately prior to the date of the effective time of the merger.

The purchase price for the merger is estimated as follows (shares in thousands):

The preliminary purchase price was computed using Westar’s outstanding shares as of June 30, 2016, multiplied by the cash consideration portion of the purchase price and adjusted for the exchange ratio for the equity portion of the purchase price. The preliminary purchase price reflects an exchange ratio calculated by dividing $9.00 by $30.3706, the 20-day volume-weighted average price per share of Great Plains Energy common stock ending on August 1, 2016. The preliminary purchase price reflects the market value of Great Plains Energy common stock to be issued in connection with the merger based on the closing price of Great Plains Energy common stock on August 1, 2016. The preliminary purchase price also reflects the total estimated fair value of Westar’s equity compensation awards settled as of June 30, 2016 as required by the merger agreement, excluding the value attributable to post-combination service.

The preliminary purchase price will fluctuate with the market price of Great Plains Energy common stock through the 20-day volume-weighted average price per share used to calculate the exchange ratio and through the value of Great Plains Energy stock issued at the close of the transaction until the purchase price is reflected on an actual basis when the merger is completed. An increase of 20% in the 20-day volume-weighted average price per share from the price used above would decrease the purchase price by approximately $107 million. A decrease of 20% in the 20-day volume-weighted average price per share from the price used above would increase the purchase price by approximately $78 million. These fluctuations assume a closing price of Great Plains Energy common stock at the effective time of the merger of $29.70, the closing price of Great Plains Energy common stock on August 1, 2016.

An increase or decrease of 20% in the Great Plains Energy closing common share price from the price used above would increase or decrease the purchase price by approximately $249 million, assuming an exchange ratio of 0.2963.

The allocation of the preliminary purchase price to the fair values of assets acquired and liabilities assumed includes pro forma adjustments to reflect the fair values of Westar’s assets and liabilities. The allocation of the preliminary purchase price is as follows (in millions):

Note 3. Adjustments to Pro Forma Financial Statements

The pro forma adjustments included in the pro forma financial statements are as follows:

Additionally, based on Great Plains Energy’s review of Westar’s summary of significant accounting policies disclosed in Westar’s consolidated historical financial statements, which are filed as Exhibit 99.1 to this Current Report on Form 8-K, as well as preliminary discussions with Westar management, the nature and amount of any adjustments to the historical financial statements of Westar to conform its accounting policies to those of Great Plains Energy are not expected to be material. Upon completion of the merger, further review of Westar’s accounting policies and financial statements may result in revisions to Westar’s policies and classifications to conform to those of Great Plains Energy.

The line items of Current maturities of long-term debt, Current maturities of long-term debt of variable interest entities and Long-term debt of variable interest entities also include pro forma adjustments to reflect Westar’s long-term debt at estimated fair value. For purposes of the pro forma adjustments, estimated fair value is based on prevailing market prices for the individual debt securities as of June 30, 2016. The final fair value determination of the debt will be based on prevailing market prices at the completion of the merger. The fair value adjustments to Westar’s regulated company debt of $461.1 million and $3.1 million within the Long-term debt and Current maturities of long-term debt line items, respectively, are offset by an increase to regulatory assets. The fair value adjustment to the long-term debt of Westar’s variable interest entities (if there continues to be a premium to book value) will be amortized as a reduction to interest expense over the remaining life of the debt.

The $4,388.7 million issuance of long-term debt (net of issuance costs of $26.3 million) reflects Great Plains Energy’s anticipated debt financing for a portion of the estimated cash consideration of the merger and other costs directly attributable to the merger.

The pro forma statements of income include the following pro forma adjustments related to long-term debt in the line item of Interest charges (in millions):

The pro forma adjustment for the incremental interest expense on the estimated $4,388.7 million of long-term debt that Great Plains Energy expects to issue includes the amortization of the estimated issuance costs over the lives of the debt issued. The incremental interest expense reflects an estimated average annual interest cost of 3.16%. A change of 0.125% in the estimated average annual interest rate would cause a change in annual interest expense of approximately $5.5 million.

The amortization of the long-term debt fair value adjustment pertains to Westar’s long-term debt of variable interest entities. The effect of the fair value adjustment is being amortized over the remaining life of the individual debt issuances, with the longest amortization period being approximately five years. The remainder of the fair value adjustments for Westar’s regulated company debt is offset by an increase to regulatory assets, and amortization of these adjustments will offset each other with no effect on earnings.

The pro forma statements of income include pro forma adjustments reflecting accumulated dividends from the issuance of these mandatory convertible preferred shares of $58.0 million and $116.0 million for the six months ended June 30, 2016 and year ended December 31, 2015, respectively. A change of 1.0% in the dividend rate of the estimated $824.5 million of mandatory convertible preferred stock would change the annual dividend amount approximately $9 million.

The pro forma balance sheet also includes pro forma adjustments reflecting the $40.1 million redemption (including a redemption premium and accrued dividends of $1.1 million) of all the outstanding shares of Great Plains Energy’s $39.0 million of 3.80%, 4.20%, 4.35% and 4.5% cumulative preferred stock which is required in order to issue the mandatory convertible preferred stock to finance the transaction. The pro forma adjustment reflecting the redemption of the cumulative preferred stock includes the reduction of $0.4 million of other current liabilities related to accrued dividends previously declared. Great Plains Energy redeemed the cumulative preferred stock in August 2016.

The pro forma statements of income also includes pro forma adjustments for the elimination of preferred dividends of $0.8 million and $1.6 million for the six months ended June 30, 2016 and year ended December 31, 2015, respectively, related to the redemption of Great Plains Energy’s 3.80%, 4.20%, 4.35% and 4.5% cumulative preferred stock.

The pro forma balance sheet also includes a $77.0 million pro forma adjustment to Interest rate derivative instruments to reflect the settlement of four interest rate swap transactions entered into by Great Plains Energy to manage interest rate risk with regards to the estimated $4,415.0 million principal amount of long-term debt that Great Plains Energy expects to issue to finance a portion of the estimated cash consideration of the merger and other costs directly attributable to the merger.

The pro forma statement of income for the six months ended June 30, 2016 includes the following pro forma adjustments related to other financing costs in the line item of Interest charges (in millions):

Both the mark-to-market impacts of interest rate swaps and the amortization of deferred financing fees for the bridge term loan facility (which Great Plains Energy expects to be fully amortized at the time of the merger) were excluded from the pro forma statements of income as they represent non-recurring charges directly attributable to the merger transaction.

See below for a detailed calculation of the pro forma weighted-average number of basic and diluted shares outstanding.

The 750,000 shares of 7.25% mandatory convertible preferred stock that will be issued to OMERS pursuant to a stock purchase agreement and the 850,000 of additional shares of 7.25% mandatory convertible preferred stock expected to be issued that are reflected in the pro forma financial statements have not been assumed to be converted in the calculation of pro forma weighted-average diluted shares outstanding for the six months ended June 30, 2016 and year ended December 31, 2015, as the conversion would be anti-dilutive. The conversion features of the 850,000 shares of mandatory convertible preferred stock have been assumed to be identical to those for the 750,000 shares of mandatory convertible preferred stock that will be issued to OMERS.