How this instrument works
Rice looks deceptively small in the measuring cup before it's cooked, because most of its final volume comes from water it hasn't absorbed yet. As it cooks, each grain soaks up water and swells, which is why a recipe written in cooked-rice cups can leave you scrambling if you only measured out the uncooked amount — the two numbers are genuinely different, not just rounding.
White rice is the most forgiving case: it roughly triples in volume when cooked, so 1 cup of the uncooked grain yields around 3 cups cooked. Brown rice expands less, since its intact bran layer slows water absorption and changes how the grain swells during cooking — the same reason brown rice also takes longer to cook than white. This calculator uses a simple 2x figure for brown rice; other published sources land anywhere from about 2x to 2.5x, so treat it as a reasonable planning round number rather than a precise constant the way the white-rice 3x figure tends to be.
These multipliers are widely repeated cooking conventions, useful for planning portions or converting a recipe between uncooked and cooked measurements, but they're an average, not a guarantee — actual expansion varies a bit by specific variety (basmati and jasmine behave slightly differently from generic long-grain), water ratio, and cooking method.
- Enter the amount of uncooked rice you're starting with, in cups.
- Select the rice type: white (roughly triples) or brown (roughly doubles).
- Read Cooked rice for the resulting volume once it's cooked.
- Use this to convert a recipe between uncooked and cooked rice measurements, or to plan portions for a group.
Worked example — 1 cup of white rice vs. 1 cup of brown
1 cup of uncooked white rice, which roughly triples in volume when cooked: cookedCups = 1 × 3 = 3 cups cooked — enough to serve as a side for roughly 4-6 people, depending on portion size.
The same 1 cup of uncooked grain, but brown instead of white: cookedCups = 1 × 2 = 2 cups cooked, a full cup less than the white result even though you started with the exact same uncooked amount — a useful thing to know if you're substituting brown rice for white in a recipe.
Scaling up to 2 cups of uncooked white rice for a bigger group: cookedCups = 2 × 3 = 6 cups cooked, showing the multiplier applies consistently regardless of the starting quantity.
Questions
Why does white rice triple but brown rice only double?
Brown rice still has its bran layer intact, which is more fibrous and slower to absorb water than the polished, bran-free surface of white rice. That slower absorption means the brown grain swells less per cup of uncooked starting material and also takes longer to cook fully. Sources vary a bit on the exact brown-rice multiplier (commonly cited figures run from about 2x up to 2.5x); this calculator uses the simpler, more widely repeated 2x round number.
Does this ratio apply to basmati or jasmine rice too?
Roughly, yes — the same approximate tripling applies to most white long-grain rice, including basmati and jasmine, though the exact multiplier can vary slightly by variety and how much water the specific recipe uses. Treat the 3x figure as a reliable planning estimate across white varieties rather than an exact figure for every single one.
How much uncooked rice should I cook per person?
A commonly cited planning figure is about 1/4 cup of uncooked rice per person for a side dish, or about 1/2 cup per person if it's the main component of the meal. Combined with this calculator's expansion factor, that works out to roughly 3/4 cup cooked rice per person as a side, or about 1.5 cups per person as a main.
Why did my rice come out with less volume than this calculator predicts?
The most common causes are undercooking (rice that hasn't fully absorbed its water won't have reached its full expanded volume) or using a lower water ratio than the recipe needs. Using significantly more or less water than a standard recipe calls for, or fluffing and measuring it differently, can also shift the result somewhat from the standard 2x-3x conventions.
Can I use this to figure out how much uncooked rice I need for a target cooked amount?
Yes — just divide instead of multiply: uncooked cups needed = target cooked cups ÷ expansion factor. For example, if a recipe calls for 6 cups of cooked white rice, you'd need 6 ÷ 3 = 2 cups of uncooked rice to start.