An estimated £1.3bn will be spent on Christmas Eve with almost 17.2 million Britons having left their shopping until the last minute.
It is thought that £55m will be spent every hour of 24 December, as research by Sainsbury's Bank Credit Cards shows 36 per cent of adults will still be shopping on Christmas Eve.
Most shoppers know how much they will be spending on gifts for their mothers, fathers, siblings and loved ones - the sum of this reaching £1.3bn.
However, a further 2.3 million people say they do not know how much they will spend on their last day of shopping, so the total amount spent could be much higher than expected.
Men, it found, are three times more likely not to budget for Christmas spending than women.
Stuart McKeggie, head of Sainsbury's Credit Cards said: "Our research indicates that Christmas Eve shopping continues to be as popular as ever, with millions of people still looking to pick up the perfect gifts right up until the last minute.
"Our research also suggests that more money will be spent on Christmas Eve in comparison to last year." In 2012, £1bn was spent on Christmas Eve.
The research has also shown how people have tried to save money on their Christmas presents this year.
Four in ten said they were using vouchers to buy food and gifts, while a quarter collected points on loyalty cards to use on their Christmas shopping.
It found eight per cent made personalised or hand-made gifts, while 13 percent plan to buy presents for loved ones in the post-Christmas sales.