Illumina (MIL:1ILMN) Operating Margin %: 19.16% (As of Mar. 2026) — Near Median

Illumina  (MIL:1ILMN) Operating Margin % Explanation

Just like Gross Margin %, it is important to see a company maintains its operating margin over time. Among the same industry, a company with higher operating margin is more efficient in its operation. It is also more stable during industry slowdown or recessions. Peter Lynch prefers those with higher margins than those with lower margins.

Be Aware

Operating Margin % can be manipulated by adjusting the rate of depreciation, depletion and amortization (DDA).

If a company is facing competition, its Operating Margin % may decline. Often the Operating Margin % declines well before the company's Revenue or even profit decline. Therefore, Operating Margin % is a very important indicator of whether the company is facing problems.

For instance, by 2012, Nokia (NOK)'s problems were well known and its stock had lost more than 90% of its market value since 2007. But Nokia’s Operating Margin % had already been in decline since 2002, although its Earnings per Share (Diluted) were still rising. Investors who paid attention to Operating Margin % would have avoided this huge loss. The same can be said for Research-in-Motion (RIMM).

Therefore, Operating Margin % is a very important screening filter for GuruFocus. GuruFocus's Buffett-Munger screener requires that the profit margin is either consistent or expanding. The Model Portfolio of the Buffett-Munger screener has outperformed the market every year since inception in 2009.

Illumina Operating Margin % Related Terms

The historical data trend for Illumina's Operating Margin % 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.

Illumina Operating Margin % Chart

Illumina Annual Data
	Trend	Dec16	Dec17	Dec18	Dec19	Dec20	Dec21	Dec22	Dec23	Dec24	Dec25
Operating Margin %		Get a 7-Day Free Trial					-2.72	7.72	-4.93	13.72	18.81

Illumina Quarterly Data
	Jun21	Sep21	Dec21	Mar22	Jun22	Sep22	Dec22	Mar23	Jun23	Sep23	Dec23	Mar24	Jun24	Sep24	Dec24	Mar25	Jun25	Sep25	Dec25	Mar26
Operating Margin %	Get a 7-Day Free Trial															15.75	20.21	20.94	18.21	19.16

MIL:1ILMN vs MTD, DGX, LH: Operating Margin % Comparison

For the Diagnostics & Research subindustry, Illumina's Operating Margin %, along with its competitors' market caps and Operating Margin % 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.

Illumina Operating Margin % vs Medical Diagnostics & Research Industry

For the Medical Diagnostics & Research industry and Healthcare sector, Illumina's Operating Margin % distribution charts can be found below:

* The bar in red indicates where Illumina's Operating Margin % falls into.

Illumina Operating Margin % Calculation

Operating Margin % - also known as operating income margin, operating profit margin and return on sales (ROS) - is the ratio of Operating Income divided by net sales or Revenue, usually presented in percent.

Illumina's Operating Margin % for the fiscal year that ended in Dec. 2025 is calculated as

Illumina's Operating Margin % for the quarter that ended in Mar. 2026 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.

Illumina Business Description