Ingenious Math Trick Allows You to Easily Calculate Percentages in Your Head

How to Calculate Percentages Trick

Stock Photos from ImageFlow/Shutterstock

If you struggle with math, the idea of calculating percentages will probably send you into a mild panic. However, thanks to the wisdom of self-confessed “maths whizz” Ben Stephens, it might be easier than you think. Stephens recently tweeted a mind-blowing math trick on how to calculate percentages in your head. His surprisingly simple solution has now gone viral and left a lot of people wondering why it wasn’t taught at school.

So what’s the secret formula? It’s simple: x% of y = y% of x. Stephens explains, “So, for example, if you needed to work out 4% of 75 in your head, just flip it and and do 75% of 4, which is easier.” If you haven’t already worked it out, the answer is 3, and the easy trick can be applied to any set of numbers. “18% of 50 feels hard to calculate,” Stephens tweeted. “But 50% of 18 is a doddle, right?” You got it—9!

Most people on Twitter reacted gratefully to Stephens’ revealing method, and some even asked if he could tutor them. “I am neither a math guy nor a teacher,” he writes. “I just learned this and thought it was cool, so I decided to share it on Twitter, and it seems to have become one of my most popular tweets ever.”

Try this new method out for yourself and see more from Stephens’ mental math conversions on Twitter.

If you struggle with how to calculate percentages, this trick revealed by “maths whizz” Ben Stephens might help.

His surprisingly simple solution has now gone viral and left a lot of people wondering why it wasn’t taught at school.

Ben Stephens: Website | Twitter
h/t [IFL Science!]

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Emma Taggart

Emma Taggart is a Staff Writer and Video Editor at My Modern Met. She earned a BA in Fashion and Textile Design at the University of Ulster in Belfast. Originally from Northern Ireland, she lived in Berlin for many years, where she fostered a career in the arts, dabbling in everything from illustration and animation to music and ceramics. She now calls Edinburgh home, where she continues to work as a writer, illustrator, and ceramicist. Her ceramics, often combined with hand-painted animation frames, capture playful scenes that celebrate freedom and movement, and blend her passion for art with storytelling. Her illustrations have been featured in The Berliner Magazine as well as other print magazines and a poetry book.
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