Some 10.1 million shoppers will visit the beleaguered high street to spend £1.38 billion on gifts and festive food and drink, while 4.8 million will spend £268 million online in the hope that their purchases can be delivered on time, according to predictions by VoucherCodes.co.uk and the Centre for Retail Research.
The anticipated rush should provide a fillip after a disappointing weekend for retailers with gales, snow and freezing rain brought by Storm Deirdre blamed for lower shopper numbers.
Combined footfall for high streets, retail parks and shopping centres was down 4.3% on the same weekend last year, according to retail intelligence experts Springboard.
Online sales are expected to peak the day before on 'Frenzied Friday' as 7.2 million shoppers spend £321 million on last-minute gifts.
Footfall is expected to be up 20% on the daily average on Super Saturday, while Sunday and Christmas Eve are anticipated to both be up by 5%, according to retail analysts ShopperTrak.
ShopperTrak UK director Steve Richardson said: "As the last working day for many before Christmas, Frenzied Friday marks the start of the last-minute festive footfall rush, with footfall set to rise across the weekend.
"Friday is also significant in that it marks the moment that shoppers move away from buying online and instead head into stores to finish off Christmas shopping.
"In spite of retailers offering later and later fulfilment options, shoppers will head on to the high street, fuelled by the fear that online gifts may not arrive in time for the big day, as well as taking advantage of click-and-collect orders, which some retailers are promising to fulfil on Christmas Eve itself."
The UK high street has been hit hard this year as several large companies entered administration including House of Fraser and Evans Cycles, which were both bought by Sports Direct tycoon Mike Ashley.
Names such as Toys R Us UK, Poundworld and electronic retailer Maplin also fell into administration, while fashion chain New Look, Marks & Spencer and Debenhams all announced store closures.
Jimmy New, director of marketing at VoucherCodes, said: "Super Saturday will be a big shopping day for both retailers and consumers alike as millions flock to stores looking to snap up last-minute gifts and other essentials before Christmas Day.
"It'll certainly be one of the busiest shopping days on the high street so, if you do brave the shops, expect crowds."
Opinium surveyed 2,003 UK adults online in October.