United States Department of Agriculture
Agricultural Research Service

National Nutrient Database for Standard Reference Legacy Release
Try FoodData Central Basic Report:  16160, Tofu, hard, prepared with nigari a 
heading Nutrient Unit
Value per 100 g

block 122 g
Proximates Water g 71.12 86.77
Proximates Energy kcal 145 177
Proximates Protein g 12.68 15.47
Proximates Total lipid (fat) g 9.99 12.19
Proximates Carbohydrate, by difference g 4.39 5.36
Proximates Fiber, total dietary g 0.6 0.7
Minerals Calcium, Ca b mg 345 421
Minerals Iron, Fe mg 2.75 3.35
Minerals Magnesium, Mg c mg 53 65
Minerals Phosphorus, P mg 231 282
Minerals Potassium, K mg 146 178
Minerals Sodium, Na mg 2 2
Minerals Zinc, Zn mg 1.66 2.03
Vitamins Vitamin C, total ascorbic acid mg 0.3 0.4
Vitamins Thiamin mg 0.042 0.051
Vitamins Riboflavin mg 0.077 0.094
Vitamins Niacin mg 0.639 0.780
Vitamins Vitamin B-6 mg 0.039 0.048
Vitamins Folate, DFE µg 22 27
Vitamins Vitamin B-12 µg 0.00 0.00
Vitamins Vitamin D (D2 + D3) µg 0.0 0.0
Vitamins Vitamin D IU 0 0
Lipids Fatty acids, total saturated g 1.445 1.763
Lipids Fatty acids, total monounsaturated g 2.205 2.690
Lipids Fatty acids, total polyunsaturated g 5.638 6.878
Lipids Fatty acids, total trans g 0.000 0.000
Lipids Cholesterol mg 0 0

Footnotes
a  Descriptive terms (soft, firm, extra firm) vary in usage between manufacturers as there are no standards for the various types of tofu.
b  Manufacturers use either magnesium chloride (nigari), calcium sulfate, or both in varying quantities to precipitate the protein. Calcium and magnesium contents will vary accordingly.
c  Manufacturers use either magnesium chloride (nigari), calcium sulfate, or both in varying quantities to precipitate the protein. Calcium and magnesium contents will vary accordingly.