Ragi, also called nachni or finger millet, contains calcium. A nutrition table may give the figure for 100 g of raw grain. To estimate one dosa or bowl of porridge, start with how much ragi went into your helping.
Work from the flour used
The Indian Food Composition Tables list about 364 mg of calcium per 100 g of raw finger millet. If a helping uses 30 g of ragi and you apply that raw-grain figure, it comes to about 109 mg from the ragi. Use the pack value when you have one, especially for mixed or processed flour.
Count the other ingredients separately
If you make porridge with milk, the milk contributes its own calcium. If you make it with water, record the ragi amount and any other ingredient you want to count. Compare ragi and oats · Indian Food Composition Tables · FSSAI finger millet reference
Raw vs cooked food weight in Indian nutrition tables
Work with the full batter
If you use 120 g of ragi flour and make four similar dosas, each dosa contains roughly 30 g of that flour. If the batter also contains rice flour, count only the ragi in the ragi calculation. When you buy a ready mix, check whether the pack gives a calcium value for the mix itself. Use that where available and write down the serving the figure describes.