🍚 Japanese Rice & Water Calculator (Gō Ratio)

Japanese rice is measured in gō (合, also written "cup" on rice cooker scales). One gō equals 180 ml or about 150 g of uncooked rice, and it is the standard portion for one bowl of cooked rice. The water you need is not a fixed ratio of weight but a volume ratio, and it changes with the type of rice:

Because you rinse, soak and cook the rice, the finished weight is about 2.2 times the raw weight for white rice. A 5.5-gō rice cooker (the most common size) fits roughly 3–4 people, while a 10-gō cooker handles 6+ people. If you are cooking for one person, half a gō (90 ml) is a typical single portion and cooks beautifully in a small cooker.

The calculator multiplies the number of gō by the water ratio for the rice type you select:

It also estimates the cooked weight (white ×330 g, brown ×300 g per gō) and recommends a cooker capacity. As a rule of thumb a 5.5-gō cooker is right for up to 4 gō of raw rice, a 10-gō cooker for up to 8 gō. The tool then converts water into both millilitres and the "cup line" marks printed inside Japanese cooker bowls, which are 180 ml each.

1. Choose the rice type (white, brown, mixed or no-rinse).
2. Enter how many gō (合) you are cooking - half-gō steps are fine.
3. Read the water amount in ml and the equivalent cup-line marks.
4. Check the cooked weight and the recommended cooker capacity.
5. Adjust water slightly for texture preferences (firmer = about 10% less).

How many ml is one gō of rice?

One gō equals 180 ml of uncooked rice, about 150 g. It is the standard volume for one serving of cooked rice, and matches the small cup that comes with Japanese rice cookers.

How much water do I add for white rice?

200 ml per gō (ratio about 1.11 : 1 by volume). For firmer rice use 190 ml, for softer rice 210 ml. The gō-line marks on the inner bowl already reflect this.

Do brown and white rice need different water?

Yes. Brown rice keeps its bran, so it absorbs more: about 250 ml per gō (ratio 1.39 : 1) plus a longer soak of 1-2 hours.

How much cooked rice does one gō make?

White rice roughly triples in weight to about 330 g per gō - two generous bowls or three side bowls. Brown rice cooks to about 300 g per gō.

What size rice cooker do I need?

A 5.5-gō cooker comfortably cooks up to 4 gō of raw rice (3-4 people). A 10-gō cooker handles 8 gō. For a single person a 2-3 gō cooker is efficient.

Can I cook half a gō?

Yes. Half a gō (90 ml rice + 100 ml water) is the standard single serving. Small cookers handle as little as 0.5 gō without burning, unlike large ones.

For most Japanese rice, the "gō line" on the inner bowl is more accurate than measuring water in a jug: fill to the mark that matches your number of gō. Wash white rice until the water runs almost clear, then soak 30 minutes in summer / 1 hour in winter before cooking. Brown rice benefits from soaking 1–2 hours or overnight. After cooking, let it steam for 10–15 minutes without lifting the lid, then fluff with a rice paddle. If you regularly cook for one, half a gō with a 180 ml "cup line" works well in a 2–3-gō cooker. For sushi or onigiri, reduce water by about 10% (to ~180 ml per gō) for a firmer texture. See our dashi calculator and Washoku recipe scaler for the rest of a Japanese meal.