Halloween is expected to make an eerily strong showing in sales this year, with consumers expected to spend as much as $6.9 billion.

This month, 157 million Americans will celebrate the holiday by spending an average of $74 per person, according to new research from the National Retail Federation, conducted by Prosper Insight & Analytics. (That number is still low compared to the average $805.65 that shoppers will spend on toys, tinsel, and Christmas trees in December.)

The 2015 Halloween Consumer Spending Survey polled more than 6,000 people during the first week of September. In a corresponding study, the NRF also ranked the most popular costumes. Richard Parrot, the president of beauty shop Ricky's NYC, has his own list of hot costume trends. 

The data reveals that celebrants will spend slightly less this year than they did in 2014, when total spending hit $7.5 billion. About 80 percent of consumers cited the state of the national economy as a reason for spending less. The figure is down from a peak of $8 billion, or $79.82 a consumer, in 2012, but still more than double the Halloween spending of a decade ago.

More than one third of consumers planned ahead by shopping before the first week in October -- that's slightly more than last year's early birds (32.1 percent of shoppers.)

Significantly, the majority of Millennials (81 percent of those surveyed) are planning to endorse Halloween, by wearing a costume, throwing a party, or dressing up their pets. 

Here's a closer look at Halloween spendings -- by the numbers:

  • Candy: $2.1 billion

The NRF puts total candy spending at $2.1 billion, although the National Confectioners Association estimates that it will be slightly more, about $2.6 billion total.

Nearly 94 percent of Halloween shoppers are planning to purchase candy.

An additional $330 million will be spent on greeting cards.

  • Costumes: $2.5 billion

A whopping $2.5 billion will be spent on costumes this year, the majority ($1.9 billion) on adult costumes. Another $950 million will be spent on children's costumes, and $350 million on costumes for pets.

This year, expect to see plenty of Minions and R2D2s, as shoppers are once again taking cues from pop-culture. For adults, vixens continue to make a strong showing (the more conservative witch costume ranks No. 1 this year.)

For the children, the No. 1 costume is a princess. Most pet owners have opted to dress their pets up in pumpkins. Increasingly, consumers are looking to Pinterest for inspiration (13.3 percent of those surveyed.) 

  • Decorations: $1.9 billion

About 45 percent of shoppers will decorate their home, cashing out for Jack-o'-lanterns, hay bales, and life-sized Minions. Sales should reach just under $2 billion, with the average shopper spending $20.34.