Calorie-Count About.com Health
Calories Burned for Activity: Ballroom
Slow (E.g. Waltz, Foxtrot, Slow Dancing), Samba, Tango, 19th C, Mambo, Chacha

204 calories per hour

Assuming a body weight of: 150 lbs
This is equivalent to eating any of the lines of the following table.

Quantity Description Cals
0.8 Grande Starbucks Caffe Latte - Made with whole milk 260
0.3 McDonald's Big Mac - With cheese 704
2.6 Glasses of wine (3.5 fl oz) 79
0.7 Snickers Bar 273
1 Cans of Coca-Cola 207
6.8 Carrots 30