[vidarh]

You probably will be far off the mark. I realized once I started tracking my food seriously that 1) those glasses I have that I though were substantially bigger than those other glasses? They held the exact same amount; 2) the amount of calories I consume could easily vary by 30% or more depending on how full I'd fill my various glasses, plates or food containers.

[waps]

I don't think getting a 30% margin of error would be all that disastrous. How big is the error margin on people measuring ?

[ehsanu1]

A 30% margin of error would seem to make calorie counting practically useless.

[waps]

I seriously doubt anyone doing calorie tracking without scales achieves less than a 30% error rate.