Uncooked to Cooked Rice Calculator

What happens when rice cooks: water, not magic

Dry rice is about 12% water and mostly starch. Simmer it and the starch granules absorb water and swell, which means the weight gain in the pot is exactly the water the rice took on. Nothing burns off in absorption cooking, and no dry matter is lost, so the calories you started with are the calories you end with, just spread across a heavier, fluffier pile of rice.

That is what makes the conversion predictable. The USDA FoodData Central database lists paired raw and cooked entries for each rice variety, and the yield falls straight out of their water contents. Raw enriched long-grain white rice holds 11.62% water; its cooked counterpart holds 68.44%. The dry matter in 100 g of raw rice is 100 - 11.62 = 88.38 g, and once cooked that same dry matter makes up 100 - 68.44 = 31.56% of the mass, so the cooked weight is 88.38 / 0.3156 = about 280 g. That is the 2.8 yield the calculator uses.

The same derivation on brown long-grain rice gives about 2.97, because the bran layer holds more water, and medium-grain white lands near 2.78. One number covers most pots, but the variety you buy shifts it, which is why the calculator asks.

Worked example: 300 g of dry rice for dinner

Say you are cooking for four and measure out 300 g of dry long-grain white rice, a bit over a cup and a half. The conversion runs:

• Cooked weight: 300 x 2.8 = 840 g of cooked rice
• Cooked cups: 840 / 158 = 5.32 cups, using the USDA cooked cup weight of 158 g
• Calories: 300 g dry at 3.65 kcal per gram = 1,095 kcal for the whole pot, unchanged by cooking

Per person, that is 210 g of cooked rice, a solid dinner side. The calorie line is worth pausing on: whether you weigh the pot's contents before cooking or after, the energy is the same 1,095 kcal. What changes is the density. Dry rice holds 365 kcal per 100 g; cooked rice holds about 130, because water now makes up more than two thirds of the weight.

Run the same 300 g in brown long-grain and the pot comes out heavier: 300 x 2.97 = 891 g. The calories are marginally different too, since brown rice holds 367 kcal per 100 g dry and about 123 per 100 g cooked. Same pot of dinner, different bookkeeping.

Yields by variety, from USDA FoodData Central

The table below shows the USDA-derived yield for the most common varieties, along with what 100 g of dry rice becomes and what a cooked 100 g portion carries. Jasmine and other aromatic long-grain whites behave like the long-grain entry for weight purposes; parboiled rice runs a touch lower because parboiling pre-gelatinizes some starch.

The last row is the honest footnote. USDA's cooked entries describe USDA's test kitchen, not yours. Water ratio, lid discipline, and simmer time all move the final weight, so a firm pilaf-style pot yields less cooked weight per dry gram and packs more calories into each 100 g. If precision matters, weigh one batch of your usual method and compute your personal yield: cooked weight divided by dry weight, done once, covers every future pot.

Cups to grams to servings

Most US recipes speak in cups, but the cup is the least reliable measure in this conversion because dry rice packs differently than cooked rice. A cup of dry long-grain white rice weighs 185 g; a cup of cooked weighs 158 g, because cooked grains are swollen and sit looser. The table converts the common portions both ways.

For serving counts, standard guidance is 50 to 75 g of dry rice per person for a side and 100 g or more when rice is the main. A typical rice cooker scoop is about 180 g dry, nearly one cup, and most cookers print serving lines on that basis. When a recipe says serves 4 with 1 cup dry, it is counting on the 3.28 cups the pot produces.

Water ratios that reach these yields

The 2.8 yield assumes the rice keeps the water it absorbs. Standard stovetop absorption ratios: 1.5 to 2 parts water to 1 part long-grain white rice by volume, 2 to 2.25 for brown, about 1.25 for jasmine, and 1.1 to 1.2 in a rice cooker, which traps steam a stovetop loses. Rinsing rice first washes off surface starch, which keeps grains separate but does not change the absorbed-water math much.

Boil-and-drain is the outlier. Cooking rice in a big pot of water and straining it produces a lower yield per dry gram because some starch and minerals go down the drain with the water, and the drained rice weighs less than absorption-cooked rice from the same starting weight. For the predictable numbers in this calculator, absorption cooking is the method it assumes.

Why the cooked weight matters for tracking food

Every rice label in the store prints nutrition per uncooked serving, usually a 1/4 or 1/2 cup of dry rice. Meal plans and restaurant menus, meanwhile, almost always speak in cooked portions. Between those two states sits a factor of nearly 3, which is why rice is the most common food-logging mistake in any tracking app.

Three scenarios show the stakes. Log 840 g of cooked rice against a raw entry and you record about 3,066 kcal for a 1,095 kcal pot, roughly tripling the count. Log 300 g of dry rice against a cooked entry and the pot comes out at 390 kcal instead of 1,095. Weigh 210 g of cooked rice correctly and log it against the cooked entry, and you get the true 273 kcal. One habit fixes all three: weigh in one state, and pick the database entry that matches it.

Leftover handling completes the loop. Cooked rice is a known carrier of Bacillus cereus, whose spores survive cooking, so the USDA leftover food safety guidance is to cool it quickly, refrigerate within an hour, and eat it within 3 to 4 days. Reheat to steaming. None of that changes the weight math, but it changes whether the 840 g you calculated is safe to eat twice.

How to use this calculator

Enter the dry rice amount in grams, or enter cups and multiply by 185 for long-grain white (a cup of medium-grain runs about 195 g and brown about 185 to 190 g). Pick the variety, and the results show the cooked weight, the cooked cup count, and the total calories, which match the dry input either way. The yields come from paired USDA FoodData Central entries for each variety, derived from their raw and cooked water contents.

Treat the outputs as the absorption-cooking case with a standard water ratio. A firm pot, a boil-and-drain method, or a wet cooker will land a bit off, and weighing one real batch will tell you your kitchen's personal factor. All calculations run in your browser, and nothing you type is uploaded or stored.