How do you guestimate how many calories??

Hi Katie! I use SparkPeople to calculate all of my calories and exercises so you could try that - I am not sure if you can use the exercise calculator without signing up for an account though.Also, a quick google search brought up http://www.prohealth.com/weightloss/tools/exercise/calculator1_2.cfm and it looks like they have an Aerobics (low impact and high impact) which might be helpful!