Floating balloons on the ceiling is all you need to kick-start the party. And there's no need to completely cover the ceiling. We recommend 20% coverage, with each balloon takes up approximately one square foot. For a room measuring 20 feet long and 10 feet wide (200 square feet), 50 balloons would do the job. For the customer who wants to completely cover the dance floor, a dance area measuring 20ft x 20ft would need 400 balloons to provide 100% coverage. In our opinion, 40-50 balloons would do a fine job.