The spending last year was worth Bt10.3 billion, which went up by 27.2 per cent from the previous year when flood disaster dampened the festive mood.
Bangkok festivities will be less cheerier, though, due to political protests as well as the mourning for the Supreme Patriarch.
The university's Economic and Business Forecasting Centre said it is estimated that the revellers would spend Bt1,539 per head on average.
Thanavath Phonvichai, the director of the centre, said that consumers are now concerned with good prices.
According to a survey by Bangkok University, over half of residents in Bangkok and peripheral provinces plan to join the annual Loy Krathong festival this year. From 1,354 respondents, the poll said 52.4 per cent plan to join the festival, while 47.6 per cent are undecided.
The event in Bangkok is their first choice, followed by the events in Chiang Mai and Sukhothai.
Notably, 79.5 per cent plan to float Krathong made of natural materials.
Generally, they perceive that the festival on November 17 would not be as big as last year. Asked what they want to float away with the Krathong, 56.4 per cent said politics, 18 per cent said conflicts, and 6 per cent said corrupted politicians.