If you’ve ever felt like your age doesn’t quite align with how old you feel inside, you could have a different mental age — and now’s your chance to figure out what it is.

An online test has taken over TikTok, with the hashtag #mentalagetest culminating in more than 15.7 million videos on the app — and many users are in shock at their results.

The trend involves people sharing their actual age before sharing their mental age results from the test — and more often than not there’s a difference of several years between them.

Users have been a mix of delighted and horrified over their newfound age. Some agree they feel a lot younger or older than they actually are while others are dumbfounded at how inaccurate it is.

“Loool, explains a lot,” one user wrote after receiving an age far older than she actually is.

“I got the same age as my mother,” one user wrote with laughing emojis.

The online test asks a series of questions to determine your “mental age.”

According to the test’s website, this test originates from Japan, and was first launched in 2013, stating it’s “very reliable.”

It also says the results of the test have nothing to do with how intelligent someone is.

“For the purpose of this test, we define Mental Age as a measure of a person’s psychological abilities in comparison to the number of years it takes for an average child to reach the same level,” it explains.

“For example, if your mental age is 10, regardless of your actual chronological age, you are mentally similar to a 10-year-old.”

To do the test, press start and follow the prompts where it will then reveal how old you are, mentally.

This story originally Appeared on NYPOST