IDKOF (Idemitsu Kosan Co) E10: $0.75 (As of Mar. 2026)

Idemitsu Kosan Co  (OTCPK:IDKOF) E10 Explanation

If a company grows much fast than inflation, E10 may underestimate the company's earnings power. Shiller PE Ratio can seem to be too high even the actual P/E is low.

For the Shiller P/E, the earnings of the past 10 years are inflation-adjusted and averaged. The result is used for P/E calculation. Since it looks at the average over the last 10 years, the Shiller P/E is also called PE10.

The Shiller P/E was first used by professor Robert Shiller to measure the valuation of the overall market. The same calculation is applied here to individual companies.

Idemitsu Kosan Co's Shiller P/E Ratio of today is calculated as

* 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 Shiller P/E Ratio of Idemitsu Kosan Co was 34.13. The lowest was 8.65. And the median was 13.83.

Be Aware

Shiller PE Ratio works better for cyclical companies. It gives you a better idea on the company's real earnings power.

Idemitsu Kosan Co E10 Related Terms

The historical data trend for Idemitsu Kosan Co's E10 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.

Idemitsu Kosan Co E10 Chart

Idemitsu Kosan Co Annual Data
	Trend	Mar17	Mar18	Mar19	Mar20	Mar21	Mar22	Mar23	Mar24	Mar25	Mar26
E10		Get a 7-Day Free Trial					0.36	0.43	0.45	0.69	0.75

Idemitsu Kosan Co Quarterly Data
	Jun21	Sep21	Dec21	Mar22	Jun22	Sep22	Dec22	Mar23	Jun23	Sep23	Dec23	Mar24	Jun24	Sep24	Dec24	Mar25	Jun25	Sep25	Dec25	Mar26
E10	Get a 7-Day Free Trial															0.69	0.62	0.71	0.70	0.75

IDKOF vs VLO, MPC, PSX: E10 Comparison

For the Oil & Gas Refining & Marketing subindustry, Idemitsu Kosan Co's Shiller PE Ratio, along with its competitors' market caps and Shiller PE 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.

Idemitsu Kosan Co Shiller PE Ratio vs Oil & Gas Industry

For the Oil & Gas industry and Energy sector, Idemitsu Kosan Co's Shiller PE Ratio distribution charts can be found below:

* The bar in red indicates where Idemitsu Kosan Co's Shiller PE Ratio falls into.

Idemitsu Kosan Co E10 Calculation

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. When we calculate the today's Shiller P/E ratio of a stock, we use today's price divided by E10.

What is E10? How do we calculate E10?

E10 is the average of the inflation adjusted earnings of a company over the past 10 years. Let's use an example to explain.

If we want to calculate the E10 of Wal-Mart (WMT) for Dec. 31, 2010, we need to have the inflation data and the earnings from 2001 through 2010.

We adjusted the earnings of 2001 earnings data with the total inflation from 2001 through 2010 to the equivalent earnings in 2010. If the total inflation from 2001 to 2010 is 40%, and Wal-Mart earned $1 a share in 2001, then the 2001's equivalent earnings in 2010 is $1.4 a share. If Wal-Mart earns $1 again in 2002, and the total inflation from 2002 through 2010 is 35%, then the equivalent 2002 earnings in 2010 is $1.35. So on and so forth, you get the equivalent earnings of past 10 years. Then you add them together and divided the sum by 10 to get E10.

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, Idemitsu Kosan Co's adjusted earnings per share data for the three months ended in Mar. 2026 was:

Current CPI (Mar. 2026) = 112.7000.

Idemitsu Kosan Co Quarterly Data

Add all the adjusted EPS together and divide 10 will get our e10.

Idemitsu Kosan Co Business Description