Uncooked to Cooked Rice Calculator

Background.

One cup of ordinary long-grain white rice cooks up to about 3¼ cups. One cup of instant white rice, which looks much the same in the bag, gives 1½. The familiar advice that rice triples is close for the first and wrong by half for the second, and the reason is processing: instant rice was cooked and dried again at the factory, so most of its swelling happened before you bought it.

The yields used here come from one table, the rice rows of the USDA Food Buying Guide for Child Nutrition Programs, the reference school kitchens use to work out how much to order. It covers nine kinds of rice, from instant white at 1.5 cups cooked per cup dry to parboiled brown at 3.625. Regular short- or medium-grain white gives 3, parboiled white 2.75, regular long-grain brown 2.889, instant brown 2.815, quick-cooking medium-grain brown 2.444, and black or purple rice 3.1.

You can work in either direction. Start from what is in the bag, by the cup or on a kitchen scale, to see how much cooked rice it will make; or start from the cooked cups a recipe or a crowd needs and get the dry amount to measure out. Weights always refer to dry rice, because the guide publishes cooked rice only as a volume.

Jasmine, basmati and wild rice are not among the guide's rice rows, so they are not offered. The figures describe plain rice simmered in water on a stove or held on a steam table; rice cookers, pressure cookers and rinsing can move the result a little.

What is uncooked to cooked rice calculator?

Rice yield is the volume of cooked rice produced by one volume of dry rice, written here as cups cooked per cup dry. Cooking adds water and swells the starch without removing dry matter, so the yield depends on how much water the grain can still take up. For five varieties the USDA guide prints the answer as a line such as "1 cup dry = about 3-1/4 cups cooked"; for the other four it gives cups dry and cups cooked per pound, and the yield is one divided by the other. Each variety also has its own weight per dry cup, taken from the same cups-per-pound figure.

How to use this calculator.

1. 01Choose the direction: uncooked to cooked when you know how much rice you have, cooked to uncooked when you know how much cooked rice you want.
2. 02Pick the variety printed on the pack. Converted rice is the parboiled kind, and rice sold as minute or ready in five minutes is generally instant.
3. 03Enter the amount. For dry rice you can use cups, grams, ounces or pounds; for cooked rice the amount is always read as cups.
4. 04Read the cooked cups, the dry cups and grams, and the serving counts if you are portioning for several people.

The formula.

Cooked cups C = uncooked cups U × R, where R is the USDA yield for the variety; the reverse is U = C ÷ R. When you enter a weight, it is first converted to dry cups using the variety's grams per cup, which is 453.59237 g (one pound, exactly) divided by the guide's cups of dry rice per pound, D. For long-grain white, D is 2⅓, so a cup weighs 194.3967 g; for instant white, D is 4½ and a cup weighs only 100.7983 g.

The four derived yields are ratios of published per-pound cells. Regular long-grain brown is listed at 2¼ cups dry and 6½ cups cooked per pound, so R = 6.5 ÷ 2.25 = 2.889. Where the guide prints both a one-cup line and per-pound cells, the one-cup line is used, and the two can differ because the cells are rounded to fractions of a cup: parboiled white divides out to 2.8 but is published as 2¾.

There is an independent check on the main 3¼ figure. USDA's FoodData Central lists raw long-grain white rice at 11.62% water and 185 g a cup, and cooked at 68.44% water and 158 g a cup. Cooking adds only water, so a dry cup's 185 × 0.8838 = 163.5 g of dry matter makes 163.5 ÷ 0.3156 = 518.1 g of cooked rice, or 3.279 cups, within 0.9% of the guide's 3.25.

The serving counts divide the cooked cups by ½, the cooked-rice portion USDA counts as one ounce-equivalent of grains, and by 1 for a generous plate.

A worked example.

Frequently asked questions.

References& sources.

1. [1]U.S. Department of Agriculture, Food and Nutrition Service. "Food Buying Guide for Child Nutrition Programs," Section 4 (Grains) yield table, heading RICE (Group H) — nine rice rows giving cups dry per pound, cups cooked per pound, and for five varieties an explicit "1 cup dry = about X cups cooked" line. Retrieved 2026-07-30; the yield-table PDF carries no printed revision date.
2. [2]U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, SR Legacy record 168877, "Rice, white, long-grain, regular, raw, enriched" (published 2019-04-01) — water 11.62 g/100 g, 365 kcal/100 g, 1 cup = 185 g.
3. [3]U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, SR Legacy record 168878, "Rice, white, long-grain, regular, enriched, cooked" (published 2019-04-01) — water 68.44 g/100 g, 130 kcal/100 g, 1 cup = 158 g. Together with record 168877 this gives an independent moisture-balance check on the 3¼× yield.
4. [4]USA Rice Federation. "How To Cook Rice" — variety-specific stovetop liquid ratios and cook times, and the general observation that rice roughly triples in volume, which this page tests against USDA's per-variety data.
5. [5]National Institute of Standards and Technology. NIST Special Publication 811 (2008 edition), Table B.8 — avoirdupois pound = 453.59237 g and ounce = 28.349523125 g exactly, used for every weight conversion here.