1 cup of cooked Spinach = about 245 mg of Calcium.
Spinach contains oxalates and that affects the absorption of Calcium to understand more - do read this article on Oxalates by whfoods.com
Spinach has a power packed nutritional profile as it is a good source of Vitamin K, Vitamin A, Folate, Magnesium, Iron, Copper and has good amounts of Vitamin B2, Vitamin B6, Vitamin E, Vitamin C plus Calcium and Potassium.
Spinach also contains phytonutrients carotenoids (lutein, neoxanthin, violaxanthin) and flavonoids (spinacetin, patuletin, jaceidin)
Do you eat 3 to 5 servings of green leafy vegetables a week?
No matter what your answer is - even if it is a maybe - do glance through - the table titled 'cup of vegetable table' available on choosemyplate.gov;