It's difficult to give a precise percentage, but current scientific evidence suggests that the vast majority of stars in the universe likely have planets orbiting around them.

Here's why:

* Kepler Mission: The Kepler space telescope, specifically designed to find exoplanets, found that at least 70% of sun-like stars have planets orbiting them. This was a major breakthrough, showing that planets are common, not rare.

* Other Exoplanet Missions: Other missions like TESS (Transiting Exoplanet Survey Satellite) have further confirmed the abundance of planets, especially in the habitable zones of stars.

* Planet Formation Theories: Our understanding of planet formation suggests that the process of forming planets is common and occurs around most stars.

However, it's important to note that:

* Detection Bias: Current methods for detecting exoplanets are biased towards larger planets closer to their stars. We are still improving our ability to find smaller, more distant planets.

* Unknown Percentage: While the evidence points towards a high percentage of stars having planets, we don't have an exact number. There are still many stars we haven't observed closely enough to detect any potential planets.

So, while it's hard to say exactly what percentage of stars have planets, it's safe to say that planets are very common in the universe.