How a little-known Finnish company became one of the world’s hottest gadget startups

Oura’s smart ring is on its fourth iteration, and millions of people rely on it for tracking their health. Like a smartwatch, it monitors things like heart rate, skin temperature and movement. But what it does with that data is different—more focused on health than fitness. For example, because the ring gathers data 24/7, its wearers wake up to a “readiness score" which factors in everything from how they slept to evidence they might be feeling stressed. These insights are a product of a huge amount of health data, including a trove volunteered by 70,000 of its users that now enables the ring to predict when a wearer is becoming sick before they show symptoms.

The Oura ring has raves from reviewers, including our own Nicole Nguyen, and has been spotted on celebrities from actors Jennifer Aniston and Tom Holland to soccer star Cristiano Ronaldo and Meta Chief Executive Mark Zuckerberg.

Founded in 2013 in Oulu, Finland’s fifth-largest city, the rise of Oura shows how a new wave of health-monitoring gadgets are appealing to everyone from self-tracking die-hards to those casually interested in improving their health, in part by doing things smartwatches cannot.

The Oura ring’s focus on living a balanced life—the ring will tell you when to rest, rather than chastising you for failing to exercise—comes directly from the Finnish culture of its founders, says head of human resources Marjut Uusitalo. She joined the company in 2016, but has known the three co-founders of the company since they first gathered friends to brainstorm the then-novel idea of a health-tracking ring several years before.

“In Finnish culture, we are really down to earth people, and nature is close to our hearts," says Uusitalo. “We have harsh winters, and very clearly differentiated seasons, and so on. We wanted to show you how to balance your life and listen to your body and give yourself a rest."

Oura had an initial crowdfunding raise of less than $1 million on Kickstarter in 2013, and in 2024 raised $200 million, at a $5.2 billion valuation. Through February of 2024, Oura had sold approximately 2.5 million rings, says chief executive Tom Hale. The company now has 700 employees worldwide, spread across Finland and the U.S.

Oura’s customers are about 55% women, and the company focuses on women’s health, including menstrual cycle tracking for well-being, conception and contraception. The ring was also used by the NBA during the height of the Covid pandemic to help predict when athletes might be coming down with the virus. Oura’s single biggest customer is the U.S. Department of Defense, which recently signed a $96 million contract to hand out its rings to service members as part of a “workforce well-being services" program.

Oura is still headquartered in Oulu, a seemingly unlikely incubator for a world-famous consumer-tech startup. A city of just over 200,000 people, it is 60 miles from the Arctic circle, 300 miles north of Helsinki, and a world away from Silicon Valley. Oulu has grown from a hub of wood-tar production and salmon fishing into a home to startups, thanks in part to the way telecom equipment maker Nokia has helped Finland attract and cultivate talent.

It has been a long journey for the company, which is on its fourth CEO. When Oura started in 2012, one of the three co-founders, Petteri Lahtela, became the company’s CEO. Four years later, another co-founder, Kari Kivelä, was in a Whole Foods in New York City and struck up a conversation with a man wearing an Oura ring. That was Harpreet Singh Rai, an investment banker who put money into Oura and, in 2018, became its second CEO, with Petteri Lahtela selling his stake.

In 2021, Rai stepped down, an interim CEO stepped in, and in 2023, Oura ring user and fan Tom Hale became CEO. He convinced the company’s leadership that his background in software and experience in growing businesses to the point they can go public in an IPO could help grow Oura. The company remains private, for now.

Along the way, Oura went through four updates to the ring’s hardware, and countless updates to its software.

Smart ring vs. watch

Using a sensor-packed ring on a finger offers a number of advantages for health tracking that are difficult for a smartwatch to match. The first is that many people feel more comfortable never taking off their ring, allowing it to track vitals during sleep, a uniquely revealing window into our health. Then there’s the way that having a sensor snug against an artery in a finger can offer up data that is difficult to gather from a smartwatch that can shift over time and is limited to the back of our wrists, and taking readings primarily from veins.

Almost two-thirds of Oura customers wear both the ring and a second wearable, usually a smartwatch, says Hale. One reason for doubling up is that the two devices can serve different functions—smartwatches have displays useful for instantaneous feedback during workouts, and in many respects have become miniature smartphones.

One powerful example of the capability of these smart rings is its ability to monitor heart health. The velocity of a pressure wave of blood flowing through an artery is a reliable indicator of the stiffness of a person’s arteries, which correlates with a range of cardiovascular diseases. This measurement powers a “Cardiovascular Age" feature on Oura rings, which tells users about their heart health—something that the Apple Watch doesn’t do.

Smart rings can also help people detect that they are becoming sick before they feel any symptoms of an oncoming illness like a cold or flu. A similar system was recently introduced on the Apple Watch, called Vitals, but such systems work best when data is gathered continuously. People who don’t sleep with their watch on might not be able to get the same insights from a watch as a ring.

With success comes competition. More than a dozen smart rings were on display at the recent Consumer Electronics Show in Las Vegas. Oura leads the pack in sales, but it now has credible challengers from fast-growing Ultrahuman, based in Bengaluru, India, as well as Paris-based Circular, and RingConn, the U.S. arm of Shenzhen-based Ninenovo Technology.

Ultrahuman CEO Mohit Kumar says its ring could catch Oura within a year. It is more likely on a longer time horizon, says Ramon Llamas, research director of IDC’s devices and displays team. The two companies are locked in a fierce race in terms of the sensors and services they offer customers, with Ultrahuman recently one-upping Oura by adding atrial fibrillation detection to its rings.

Ultrahuman doesn’t charge a subscription fee, while Oura charges $6 a month. Hale, head of Oura, says this fee is essential to continued investment in the ring, including funding more than 30 in-house Ph.D.s dedicated to research and development.

Oura has a formidable weapon with its substantial portfolio of patents. Amaury Kosman, chief executive of Circular, says this portfolio could be a barrier to other entrants into this space. Kosman’s company has licensed Oura’s entire patent portfolio, and pays a fee for every ring it sells. Oura has filed complaints with the U.S. International Trade Commission alleging infringement of its IP by both RingConn and Ultrahuman. If Oura wins, it would mean that devices from both companies would be banned from being imported to the U.S. Oura’s complaint is in process, and rings from both companies are still available in the U.S.

Taking miniaturization to an extreme

Today’s smart rings are the result of decades of breakthroughs in miniaturization of electronics, as well as new designs that take power saving for sensors and microchips to an extreme, says Joshua R. Smith, a professor of engineering at the University of Washington.

While today’s smartphones typically run on chips designed by the likes of Apple, Qualcomm and MediaTek, most smart rings run on chips mere millimeters on a side, made by Nordic Semiconductor, based in Trondheim, Norway. Its chips are typically found in things like computer peripherals, toys, and internet of things sensors.

To measure things like heart rate and skin temperature, Oura and other smart rings use sensors that produce and detect light. The sensors in smart rings come from manufacturers in China and Europe, says Kumar of Ultrahuman, which assembles its rings in the company’s hometown of Bengaluru.

Worldwide, 1.8 million smart rings were sold in 2024, for about $500 million in revenue, says Llamas. He projects that growth will be slow and steady in the future, with global revenue for smart rings approaching $900 million in 2029.

When it comes to competition with tech giants like Apple, Oura may have the advantage of being too small to threaten them—at least for the foreseeable future.

“I think we are maybe advantaged by having a really specific focus," says Hale. Apple has a large health team, but also needs to move the needle at a company with nearly $400 billion in revenue. For a consumer tech startup like Oura, on the other hand, just getting to its current size has been something of a miracle.