Delta Air Lines (WBO:DAL) Cyclically Adjusted Book per Share: €17.61 (As of Jun. 2026)

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WBO:DAL Delta Air Lines Inc WBO:DAL
79 GF Score
Price €67.64
GF Value €51.87
Valuation Modestly Overvalued
! 4 Warning Signs
View Full Analysis

What is Delta Air Lines Cyclically Adjusted Book per Share?

Delta Air Lines WBO:DAL -0.97% 79 Cyclically Adjusted Book per Share is €17.61 as of Jun. 2026. GuruFocus rates WBO:DAL with a GF Score™ of 79/100 and a GF Value™ of €51.87 (Modestly Overvalued). The stock has 4 warning signs investors should review.

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller PE Ratio calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted Book per Share and the Cyclically Adjusted PB Ratio. The Cyclically Adjusted Book per Share is the average of the inflation adjusted Book Value per Share of a company over the past 10 years.

Delta Air Lines's adjusted book value per share for the three months ended in Jun. 2026 was €29.015. Add all the adjusted book value per share for the past 10 years together and divide the count will get our Cyclically Adjusted Book per Share, which is €17.61 for the trailing ten years ended in Jun. 2026.

During the past 12 months, Delta Air Lines's average Cyclically Adjusted Book Growth Rate was 10.00% per year. During the past 3 years, the average Cyclically Adjusted Book Growth Rate was 7.80% per year. During the past 5 years, the average Cyclically Adjusted Book Growth Rate was 9.20% per year. Please click Growth Rate Calculation Example (GuruFocus) to see how GuruFocus calculates Wal-Mart Stores Inc (WMT)'s revenue growth rate. You can apply the same method to get the Cyclically Adjusted Book Growth Rate using Cyclically Adjusted Book per Share data.

During the past 13 years, the highest 3-Year average Cyclically Adjusted Book Growth Rate of Delta Air Lines was 41.80% per year. The lowest was -90.80% per year. And the median was 5.10% per year.

As of today (2026-09-15), Delta Air Lines's current stock price is €67.64. Delta Air Lines's Cyclically Adjusted Book per Share for the quarter that ended in Jun. 2026 was €17.61. Delta Air Lines's Cyclically Adjusted PB Ratio of today is 3.84.

During the past 13 years, the highest Cyclically Adjusted PB Ratio of Delta Air Lines was 22.81. The lowest was 1.67. And the median was 3.47.


Delta Air Lines  (WBO:DAL) Cyclically Adjusted Book per Share Explanation

If a company grows much fast than inflation, Cyclically Adjusted Book per Share may underestimate the company's equity. Cyclically Adjusted PB Ratio can seem to be too high even the actual PB Ratio is low.

For the Cyclically Adjusted PB Ratio, the book value of the past 10 years are inflation-adjusted and averaged. The result is used for P/B calculation. Since it looks at the average over the last 10 years, the Cyclically Adjusted PB Ratio is also called CAPB Ratio.

The Shiller PE Ratio was first used by professor Robert Shiller. He uses E10 for his Shiller PE Ratio calculation. E10 is the average of the inflation adjusted earnings per share of a company over the past 10 years. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted PB Ratio. The Cyclically Adjusted Book per Share is the average of the inflation adjusted book value per share of a company over the past 10 years.

Delta Air Lines's Cyclically Adjusted PB Ratio of today is calculated as

Cyclically Adjusted PB Ratio=Share Price/Cyclically Adjusted Book per Share
=67.64/17.609
=3.84

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

During the past 13 years, the highest Cyclically Adjusted PB Ratio of Delta Air Lines was 22.81. The lowest was 1.67. And the median was 3.47.


Be Aware

Cyclically Adjusted PB Ratio works better for cyclical companies. It gives you a better idea on the company's real book value.


Delta Air Lines Cyclically Adjusted Book per Share Related Terms


Delta Air Lines Cyclically Adjusted Book per Share Historical Data

* Premium members only.

The historical data trend for Delta Air Lines's Cyclically Adjusted Book per Share can be seen below:

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

Delta Air Lines Cyclically Adjusted Book per Share Chart

Delta Air Lines Annual Data
Trend Dec16 Dec17 Dec18 Dec19 Dec20 Dec21 Dec22 Dec23 Dec24 Dec25
Cyclically Adjusted Book per Share
Get a 7-Day Free Trial Premium Member Only Premium Member Only 12.03 14.02 14.74 16.27 17.67

Delta Air Lines Quarterly Data
Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26 Jun26
Cyclically Adjusted Book per Share Get a 7-Day Free Trial Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only 16.11 16.43 16.64 17.18 17.61

WBO:DAL vs UAL, LUV, AAL: Cyclically Adjusted Book per Share Comparison

For the Airlines subindustry, Delta Air Lines's Cyclically Adjusted PB Ratio, along with its competitors' market caps and Cyclically Adjusted PB Ratio data, can be viewed below:

* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.


Delta Air Lines Cyclically Adjusted PB Ratio vs Transportation Industry

For the Transportation industry and Industrials sector, Delta Air Lines's Cyclically Adjusted PB Ratio distribution charts can be found below:

* The bar in red indicates where Delta Air Lines's Cyclically Adjusted PB Ratio falls into.


WBO:DAL
79GF Score
Delta Air Lines Inc WBO:DAL
Cyclically Adjusted Book per Share is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

Delta Air Lines Cyclically Adjusted Book per Share Calculation

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller PE Ratio calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted Book per Share and the Cyclically Adjusted PB Ratio. The Cyclically Adjusted Book per Share is the average of the inflation adjusted Book Value per Share of a company over the past 10 years.

What is Cyclically Adjusted Book per Share? How do we calculate Cyclically Adjusted Book per Share?

Cyclically Adjusted Book per Share is the average of the inflation adjusted Book Value per Share of a company over the past 10 years. Let's use an example to explain.

If we want to calculate the Cyclically Adjusted Book per Share of Wal-Mart (WMT) for Dec. 31, 2010, we need to have the inflation data and the book value per share from 2001 through 2010.

We adjusted the 2001 book value per share data with the total inflation from 2001 through 2010 to the equivalent book value in 2010. If the total inflation from 2001 to 2010 is 40%, and Wal-Mart's book value is $1 a share in 2001, then the 2001's equivalent book value in 2010 is $1.4 a share. If Wal-Mart's book value is $1 again in 2002, and the total inflation from 2002 through 2010 is 35%, then the equivalent 2002 book value in 2010 is $1.35. So on and so forth, you get the equivalent book value per share of past 10 years. Then you add them together and divided the sum by the count to get Cyclically Adjusted Book per Share.

Please note that we use the CPI data of the country/region where the company is headquartered. If the CPI data for that country/region is not available, then we will use the CPI data of the United States as default.

For example, Delta Air Lines's adjusted Book Value per Share data for the three months ended in Jun. 2026 was:

Adj_Book= Book Value per Share /CPI of Jun. 2026 (Change)*Current CPI (Jun. 2026)
=29.015/333.9520*333.9520
=29.015

Current CPI (Jun. 2026) = 333.9520.

Delta Air Lines Quarterly Data

Book Value per Share CPI Adj_Book
201609 15.117 241.428 20.910
201612 15.942 241.432 22.051
201703 16.455 243.801 22.540
201706 16.322 244.955 22.252
201709 16.611 246.819 22.475
201712 14.755 246.524 19.988
201803 14.535 249.554 19.451
201806 15.927 251.989 21.107
201809 17.209 252.439 22.766
201812 17.609 251.233 23.407
201903 17.555 254.202 23.062
201906 18.851 256.143 24.577
201909 21.371 256.759 27.796
201912 21.286 256.974 27.662
202003 20.445 258.115 26.452
202006 12.130 257.797 15.713
202009 4.489 260.280 5.760
202012 1.965 260.474 2.519
202103 0.641 264.877 0.808
202106 1.688 271.696 2.075
202109 3.461 274.310 4.214
202112 5.341 278.802 6.398
202203 4.126 287.504 4.793
202206 5.594 296.311 6.305
202209 7.189 296.808 8.089
202212 9.617 296.797 10.821
202303 8.812 301.836 9.750
202306 11.539 305.109 12.630
202309 13.542 307.789 14.693
202312 15.624 306.746 17.010
202403 16.000 312.332 17.108
202406 17.906 314.175 19.033
202409 18.948 315.301 20.069
202412 22.845 315.605 24.173
202503 21.901 319.799 22.870
202506 22.754 322.561 23.558
202509 24.532 324.800 25.223
202512 27.184 324.054 28.014
202603 26.917 330.213 27.222
202606 29.015 333.952 29.015

Add all the adjusted book value per share together and divide the count will get our Cyclically Adjusted Book per Share.

What does a Cyclically Adjusted Book per Share of €17.61 mean?
Delta Air Lines (WBO:DAL) has a Cyclically Adjusted Book per Share of €17.61 as of Jun. 2026. Cyclically adjusted book value per share represents the company's inflation-adjusted book value per share over a 10-year period. View historical data on Delta Air Lines and its competitors.
Is Delta Air Lines' Cyclically Adjusted Book per Share too high?
Delta Air Lines' current Cyclically Adjusted Book per Share is €17.61. Overall, Delta Air Lines has a GF Score™ of 79/100 and is considered Modestly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Delta Air Lines' Cyclically Adjusted Book per Share compare to UAL and LUV?
Delta Air Lines' Cyclically Adjusted Book per Share of €17.61 can be compared against companies in the Transportation industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Cyclically Adjusted Book per Share for a Transportation company?
A good Cyclically Adjusted Book per Share depends on the Transportation industry context. However, Cyclically Adjusted Book per Share should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Cyclically Adjusted Book per Share mean?
A high Cyclically Adjusted Book per Share can signal that a stock is expensive relative to its fundamentals. Cyclically adjusted book value per share represents the company's inflation-adjusted book value per share over a 10-year period. View historical data on Delta Air Lines and its competitors. Delta Air Lines's current Cyclically Adjusted Book per Share is €17.61. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Delta Air Lines stock overvalued right now?
Based on GuruFocus' analysis, Delta Air Lines (WBO:DAL) is currently considered Modestly Overvalued. The stock's GF Value™ is €51.87, compared to a current price of €67.64 — trading 30.4% above its estimated fair value. The current Cyclically Adjusted Book per Share is €17.61. Delta Air Lines' overall GF Score™ is 79/100 with 4 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Cyclically Adjusted Book per Share calculated?
Cyclically Adjusted Book per Share is calculated from a company's financial statements. For Delta Air Lines (WBO:DAL), the current Cyclically Adjusted Book per Share is €17.61 as of Jun. 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.

Is Delta Air Lines (WBO:DAL) Overvalued in 2026?

Based on GuruFocus' analysis, Delta Air Lines stock appears to be overvalued. The current stock price of €67.64 is trading 30.4% above its estimated GF Value™ of €51.87. GuruFocus considers Delta Air Lines to be Modestly Overvalued.

Key valuation signals for WBO:DAL:

  • Cyclically Adjusted Book per Share: €17.61
  • GF Value™: €51.87 vs. price of €67.64 (30.4% above fair value)
  • GF Score™: 79/100 with 4 warning signs

No single metric tells the full story. See the WBO:DAL stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


Delta Air Lines Business Description

Address Post Office Box 20706, Atlanta, GA, USA, 30320-6001
Atlanta-based Delta Air Lines is one of the world's largest airlines, with a network of over 300 destinations in more than 50 countries. Delta operates a hub-and-spoke network, where it gathers and distributes passengers across the globe through its biggest hubs in Atlanta, New York, Salt Lake City, Detroit, Seattle, and Minneapolis-St. Paul. Delta has historically earned most of its international revenue and profits from flying passengers over the Atlantic Ocean.
79GF Score

Get the complete analysis for WBO:DAL

Cyclically Adjusted Book per Share is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

€67.64
Price
€51.87
GF Value