NEW YORK, July 10: Many people don’t give much thought to how long they spend in the bathroom, but researchers say there is an optimal duration for a healthy pee — and it’s tied to overall health.

The magic number? About 21 seconds.

According to scientists from the Georgia Institute of Technology, 21 seconds is the ideal length of time for urination. Long enough to hum the chorus of Happy Birthday but not quite long enough for Bohemian Rhapsody.

This “21-second rule” comes from the researchers’ discovery of the so-called “Law of Urination.” They investigated how animals of vastly different sizes manage to empty their bladders in roughly the same amount of time.

By timing video clips of mammals urinating, they found that animals weighing over three kilograms take about 21 seconds to fully empty their bladders, regardless of size.

How does this happen? It’s physics. Larger animals have longer and wider urethras. The increased length boosts gravitational pressure to push urine out faster, while the wider diameter reduces resistance. This means even an elephant, with a bladder many times larger than a dog’s, finishes peeing in about the same time.

Humans follow this pattern too. Most adults take roughly 20 to 25 seconds to urinate at a relaxed pace, making the 21-second mark a useful, though flexible, benchmark.

While you don’t need to time yourself on the toilet, sudden or consistent changes in how long you take to pee can signal health issues. Very short durations combined with frequent urges might indicate an overactive bladder or other urinary problems. On the other hand, much longer times could suggest urinary retention, prostate enlargement in men, or nerve issues.

Experts also warn against holding urine for too long, as this can overstretch the bladder over time and increase the risk of infections and other complications.

Though 21 seconds isn’t a strict rule for everyone, paying attention to your usual bathroom habits can help detect early signs of health problems. So next time nature calls, consider whether your visit fits the healthy 21-second window.