Dating shoe size

Hit another button and the laces tighten a little more—if you’re about to start up an intense workout, say, or you just want an extra-snug fit.

The blue box also lights up as a row of LEDs pulse across the back of the heel.

Size six is the new four (for women), and size 10 the new eight (for men). Retailers whose upper shoe sizes stopped at 12 are now stocking sizes 13 and 14 as standard.

Our feet are getting bigger, increasing by an average of two sizes over the past four decades, according to the College of Podiatry. Requests for sizes 6 and 7 used to be common from men. The average shoe for women is also becoming broader and longer. In the US, the average female foot was a 6.5 in the 1960s (equivalent to UK size 4), rising to 7.5 in the 1970s (UK 5).

That deceptively simple technology is the product of a decade of work in Nike’s most secretive labs, where a team led by legendary designers Mark Parker, Tinker Hatfield, and Tiffany Beers created the real-life version of Mc Fly’s MAGs that Parker and Hatfield first designed back in 1988.

In the world of shoes, things are changing, and not always for the better.

We’ll admit we expected the Hyper Adapts to be a bit clunky—at 14 ounces, a size 9 is certainly heftier than your average cross-trainer—but they feel surprisingly light.

We wore the Hyper Adapts through a quick basketball practice, a treadmill run, and agility drills, and in each case, it was surprisingly helpful to quickly loosen the laces (when on the run) or lock things down (when cutting across turf) with a simple button tap.

Basically, the Hyper Adapt works by giving your feet a hug. A close-up of the adaptive "self-lacing" @nike Hyper Adapt 1.0 (aka "the Back to the Future shoe") out today in NYC.

Research in Turkey in 2011, however, was less certain.

It found a vague correlation between height, weight, BMI (body mass index) and penis size, but not enough evidence to suggest feet alone can determine it.

These charts will help you convert a simple foot measurement into your shoe size and width, and will also help you find out what sizes you take in other parts of the world.

They won't replace trying on a pair of shoes for yourself, but they can help you estimate or convert your shoe size before ordering online.