Socks Loss Index
Calculate how many socks go missing from your laundry each month and year. Free sock loss index calculator using proven formula with charts and cost breakdown.
About This Calculator
The Sock Loss Index Calculator helps you estimate how many socks disappear from your household laundry each month and year. Based on a research-backed formula developed by psychologist Dr. Simon Moore and statistician Geoff Ellis in a study commissioned by Samsung, this calculator factors in your household size, laundry habits, precautions, and attitude toward doing laundry to predict your sock loss rate and the annual cost of replacing missing socks.
The formula calculates a Sock Loss Index (SLI) score: SLI = (people × washes per week) + (types of wash × socks per week) - (attitude × (precautions + 1)). The laundry size component captures how many total washes your household produces, while the washing complexity component accounts for how many sock-handling opportunities exist. The attention penalty subtracts a factor based on your positivity toward laundry multiplied by precautions taken—the more carefully you handle laundry, the fewer socks go missing. The raw score is then converted into estimated socks lost per month and per year. A typical household of four with average precautions loses 40–60 socks per year, costing ₹2,000–₹5,000 in India, $50–$150 in the US, and £40–£100 in the UK depending on sock quality.
Regional Notes: Laundry habits vary by region. In India, many households rely on manual washing or domestic help, which can reduce sock loss compared to machine washing. In the US and UK, front-loading washing machines are common and socks can get trapped in rubber seals and drain pumps. The Sock Loss Index adapts to your specific inputs regardless of region, making it useful for households worldwide.
Frequently Asked Questions
What is the Sock Loss Index?
The Sock Loss Index (SLI) is a formula developed by psychologist Dr. Simon Moore and statistician Geoff Ellis to estimate how many socks go missing from your laundry. It factors in household size, wash frequency, washing complexity, precautions taken, and your attitude toward doing laundry.
How is the Sock Loss Index calculated?
The formula is SLI = (people × washes per week) + (types of wash × socks per wash) - (attitude × (precautions + 1)). This gives a raw index score. Higher values mean more socks are likely to go missing. The score is then converted to estimated socks lost per month and per year.
How many socks does the average person lose?
According to a study commissioned by Samsung and conducted by Dr. Simon Moore, the average Brit loses approximately 1.3 socks per month, which translates to about 15 socks per year. A family of four can lose over 60 socks annually, costing around £100 or more depending on sock quality.
Where do missing socks go?
Socks can end up between the inner and outer drum of the washing machine, in drain pipes, behind agitators, or behind radiators and furniture. However, the primary cause is human absentmindedness—socks dropped during sorting or folding, blown off clotheslines, or misplaced in bedrooms and laundry rooms.
How can I reduce my Sock Loss Index?
You can reduce sock loss by using mesh laundry bags for socks, checking washing machine seals and drums regularly, using sock clips on clotheslines, reducing the number of sock types you own, and paying more attention during laundry sorting. The study found that colored socks make up 55% of missing socks, so switching to white or striped socks may help.
What precautions count toward the formula?
Precautions include checking pockets before washing, unrolling sleeves, turning clothes right-side out, and unrolling socks. Each precaution you regularly take reduces your Sock Loss Index score, meaning fewer socks go missing.
Does the Sock Loss Index apply worldwide?
Yes, the formula is based on universal laundry habits and applies to households worldwide. In the US, the average household loses 10–20 socks per year. In the UK, studies report around 15 socks per person annually. In India, where laundry practices vary by region and household size, the index adapts to your specific inputs.
What is the most efficient way to sort socks?
Cognitive scientist Professor Brian Christian recommends the radix sort algorithm: separate socks into subgroups by color, then by length, and match within those smaller piles. Alternatively, buy only one type of sock so all socks are interchangeable, eliminating the need for sorting entirely.