That happens to me to,I just keep playing with it until I at least can put the carb count in even if the calorie count is wrong.I know thats not the proper way to do it but it won't let you put it in if it doesn't add up to that formula I can't remember what it is, I'd need a calculator . I had troble using Fitday when I first started but wasn't noticing the amount it was putting in for me,but now I find it very useful.Anyway I'll be watching if anyone knows the correct way to fix that problem. SJ