It’s a math problem, and the most problematic part is the answer. According to this calories burned chart, walking burns about 250 calories an hour. And according to this Thanksgiving calorie counter, a Thanksgiving meal delivers 4,575 calories. Hmm. So how long would it take to walk off a Thanksgiving dinner? If you start walking tonight at 7 p.m., you will burn the last of your Thanksgiving related calories 18 hours later, at 1 p.m. tomorrow.