Hi P.G.
It is a very simple calculation. Divide the % Ca by the number of kcals/kg then multiply the result by 10,000.
The percent Calcium tells you how many grams of Ca are in 100 grams of food. 1.2% Ca is equivalent to saying there are 1.2 grams of Ca in every 100 grams of food.
If you multiply the % Ca by a factor of 10 that gives you how many grams of Calcium are in a thousand grams of food ( kg) of food; in this case 12
We want to know how many grams of Calcium are in a kcal of food. If the food had 3500 kcals/kg dividing 12 grams/kg by 3500 kcals/kg = .0034grams Calcium/kcal
It is typical to express nutrients on a “per thousand” kcal basis. So multiply the number of grams in a kcal by 1000. In this case the result is 3.4 grams/1000kcals
To state another way (1.2 x 10/3500) X 1,000/1 =3.4 grams/kg which is the same as 1.2/3500 X 1000 X 10 or 1.2/3500 x 10,000.
Hope this helps!
