How long should you really take to pee?

It turns out there really is an answer to the question: “How long should I pee?”

You might not think much about the time you spend on the loo. But according to researchers, there’s an average “just right” duration for a healthy wee – and it’s linked to your overall health.

The magic trickling number is 21 seconds.

Long enough to hum the chorus of Happy Birthday but not quite long enough for Bohemian Rhapsody.

This ‘21-second rule’ has come from a group of researchers at Georgia Institute of Technology, who developed the ‘Law of Urination’.

And, while it sounds like a fun pub trivia fact, it actually reveals a surprising truth about how our bodies work, and why big changes in your bathroom habits could signal something is up.

The science behind the 21-second Law of Urination

Researchers at Georgia Tech set out to answer a deceptively simple question: how do animals of vastly different sizes manage such similar bathroom times?

They spent their days streaming (see what I did there) and timing clips of animals emptying their bladders.

They discovered that mammals weighing over about 3 kilograms tend to take around 21 seconds to urinate, no matter their size beyond that threshold.

How is that even possible? It’s all about physics. Larger animals have longer and wider urethras. The extra length increases gravitational pressure, pushing urine out faster, while the wider diameter reduces resistance.

The result: even though an elephant’s bladder holds many times more than a dog’s, both can finish in roughly the same time.

Evolution seems to have fine-tuned mammalian plumbing for efficient emptying in about 20 seconds.

What it means for humans

Humans fit this pattern, too.

Most adults typically take around 20–25 seconds to fully empty their bladders at a normal, relaxed pace.

Health professionals sometimes refer to this “21-second rule” as a loose benchmark.

Don’t start taking a stopwatch with you to twinkle, but big changes in how long you take to pee can be worth noting.

Consistently much shorter durations, especially with frequent urges, might indicate an overactive bladder or other urinary issues.

Taking much longer could suggest urinary retention, prostate enlargement in men, or nerve-related problems.

Holding it in too long can also overstretch the bladder over time, increasing the risk of infections and other complications

While 21 seconds isn’t a rigid rule for everyone, significant changes from your normal pattern can be an early sign to check in with your doctor.

Something to keep in mind the next time nature calls.