I see that total carbs are not measured as 4 calories per gram. How are they calculated?

doodle

When I check total carbs against your figure on the macro wheel, they never add up to 4 calories per gram. How do you calculate them, please?

haildodger

Hilary July 2018
The calories and the macronutrient values will be a bit off because each food is different in the actual amount of energy (calories) it contains.
What I mean here is that you were probably taught the rule that carbs and protein are 4 kcals per gram, and fat is 9 kcals per gram. They are not. They are close but there is better data on some foods and we use that in the calculations for the macronutrients.
For example, some carbs are 3.8, 4.1, 4.3 kcals per gram etc. Same is true for protein and fats. That is why there will be a discrepancy, when our data is more accurate then the 4-4-9 crude estimation.

doodle

I suspected so, thanks!