Shoplifters cost UK stores £4.4bn in the year to the end of June, a survey of 42,000 European retailers suggests.
More than a third of thefts were carried out by shop staff, said the Centre for Retail Research.
The total cost was 5.8% lower than the previous year, but theft adds about £180 to the average family's annual shopping bill.
Branded clothing is the most common target, but meat, cheese, alcohol and seafood are also often taken.
Retailers say the UK still has one of the worst records in the world.
The survey, carried out on behalf of retail security company Checkpoint Systems, found that an average of £12,054,794 worth of goods were stolen every day in the UK in the 12 months to 30 June.
Neil Matthews, from Checkpoint Systems, said a typical "theft spree" saw £93 worth of goods taken.
"While the amount stolen in the UK may well have gone down, that doesn't mean the overall impact on the general public is any less significant," he said.
"Shoplifting results in a £180 financial burden on every family in the country and so there is a real social obligation on the retail industry to do everything it can to tackle retail crime.
"Retailers are definitely making strides in the fight against shoplifting and their efforts have already started to pay dividends."
About £970m was spent on increased retail security last year, but it did not stop UK stores being targeted by their own staff.
Dr Adrian Beck, head of criminology at the University of Leicester, told the BBC: "In an organisation, it could be that there are very few controls, that you're badly paid, the morale is very low, and you realise that the risk of being caught is also very low.
"Then people are much, much more likely to take the opportunities that are presented to them."