Dry or cooked: why grain and pasta calories differ so much
How many calories are in cooked buckwheat, rice, pasta and legumes, why 100 g dry and 100 g cooked are different things, and how to weigh them.
· 2 min read · updated
A pack of buckwheat says over 300 kcal per 100 g, while tables list around 90 for cooked porridge. There’s no mistake: the first is dry grain, the second is boiled. Grains absorb water when cooked, their weight grows two to five times, and the calories stay the same — just spread over more grams.
What 100 g of dry grain becomes
| Food | Dry, 100 g | Yield | Boiled, 100 g |
|---|---|---|---|
| Buckwheat | 346 kcal | ×3.76 | 92 kcal |
| White rice | 359 kcal | ×2.76 | 130 kcal |
| Brown rice | 366 kcal | ×2.98 | 123 kcal |
| Pasta | 371 kcal | ×2.35 | 158 kcal |
| Millet | 378 kcal | ×3.18 | 119 kcal |
| Bulgur | 342 kcal | ×4.12 | 83 kcal |
| Pearl barley | 352 kcal | ×2.86 | 123 kcal |
| Oats | 389 kcal | ×5.48 | 71 kcal |
| Lentils | 352 kcal | ×3.03 | 116 kcal |
| Chickpeas | 378 kcal | ×2.3 | 164 kcal |
Yield is how many times the weight grows when boiled; we derive it from raw–cooked pairs in USDA FoodData Central. Actual yield depends on the water and cooking time: runnier oatmeal or softer porridge weighs more, so 100 g has even fewer calories.
A common mistake is counting cooked buckwheat at the dry-grain value. 200 g of cooked porridge is about 185 kcal, not 690.
How to weigh it
- Most accurate: weigh the dry grain before cooking — its calories don’t depend on how much water you add.
- If you weigh the cooked food, mark the weight as cooked in the diary: the calculator will adjust for the yield.
- Cooking for the whole family? Weigh the dry grain, then the whole finished pot, and create your own recipe with the exact finished weight.
What about vitamins?
Calories and protein don’t disappear when boiled, but some B vitamins break down or leach into the water, and minerals partly wash out too. The calculator takes how much from the same USDA raw–boiled pairs for each grain: cooked buckwheat keeps about 68% of its vitamin B1 and 87% of its magnesium, while pasta, whose water is drained, keeps only 52% of its B1. For foods without such a pair these are approximate percentages for the nutrient group. More in How we calculate.
Work out your targets
The calculator sets your daily calories, macros, vitamins and minerals, and the diary tells you which foods are better not combined.
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