Other garments languishing in wardrobes have fallen out of fashion or out of favour with their owner.
British women own an average of 14 unused items costing an average of £21.82 a piece, totalling just over £305, a survey for Churchill Home Insurance found.
Shoes top the list of items which women buy and do not wear, while shirts are the "most unworn" item of men's clothing.
Women collectively own around £7.3bn worth of clothes they do not wear with each spending around £12,810 during their working life, the insurer said.
By contrast, men have an average of nine items of clothing they have not worn in the past year, each with a price tag averaging £18.68. This adds up to £7,901 worth of unwanted clothes over their working life.
The January sales are the time when women are most likely to buy such garments.
The online survey of more than 2,500 people carried out last month revealed that 63 per cent of women had bought clothes that were a size too small at some point. And one in 10 female shoppers admitted buying smaller clothes on a regular basis.
Charity shops gain the most from shoppers' impulse buys as three-quarters of men and women donate their unwanted item, the poll found.