It’s one of the unanswered questions that has plagued humanity since the invention of the washing machine – why do we lose so many socks? And where do they go to?

It turns out that it’s not the sock fairy, or whoever tangles headphones when you’re not watching. Science now has an answer for why we lose so many socks in our lifetime.

According to new research, Britons lose 1.3 socks on average per month, or 15 a year – a whopping 1,264 in the average lifetime. Losing socks costs us on average £2528!

After surveying 2000 people, psychologist Dr. Simon Moore and statistician Geoff Ellis came up with a mathematical formula, the ‘Sock Loss Index’, which explains why we keep losing socks.

(L(p x f) + C(t x s)) – (P x A)

Key: Laundry size (L), number of people in household (p), frequency of washes (f), Complexity of wash (C), type of wash (t), number of socks washed in a week (s), positivity towards doing the washing (P), level of attention being paid to the task (A)

In other words, the probability of sock loss equals laundry size plus the complexity of the wash minus the level of attention being paid to the task multiplied by the person’s attitude towards doing the washing. The larger the wash, the higher the chance of losing socks.

“In simple terms the complexity of the wash load and your attention to detail during the cleaning process, are the factors with the biggest impact on sock loss,” the researchers said.

According to the survey, the top themes contributing to sock loss during washing are:

Noone taking responsibility for the washing

Not looking for lost socks properly

Confirmation bias – if we can’t see any odd socks, we convince ourselves that there are no odd socks

Human error – failing to put a sock in the wash in the first place