Short answerA Japanese rice cooker cup holds 180 mL, while a US measuring cup is 240 mL. If you measure rice with a US cup and fill water to the pot's lines, you get too little water for the amount of rice.
Zojirushi measures its rice cooker capacity with a 180 mL rice measuring cup (about 6.1 fl oz). The FDA's labeling guidance defines 1 cup as 240 mL. One US cup is therefore about 1.33 rice cups, and one rice cup is three quarters of a US cup.
Fig. 1Pot capacity in liters
The water lines printed inside the inner pot are numbered in rice cups. Put in 2 US cups of rice and fill to the "2" line, and you have about 2.7 rice cups of rice with water for 2. Use the cup in the box for rice, then the line for water, and you do not need to convert at all.
A 3-cup Micom cooker for one or two people. It adds settings Americans actually use: long-grain white, GABA brown and steel cut oatmeal.
Good forYou live alone or as a couple. You want oatmeal in the morning from the same machine.
Watch outYou meal-prep rice for the whole week.
Zojirushi's long-running 5.5-cup Micom model. Bottom heating with fuzzy logic, a retractable cord and a steam basket. The safe, simple pick if you mostly cook white rice.
Good forYou want a proven Zojirushi without paying for IH. You cook white or sushi rice most days.
Watch outYou want the fastest cook times or the most even heating (IH models do better).
Tiger's basic 1-liter Micom cooker with the tacook plate, which cooks a main dish on top while the rice cooks underneath.
Good forYou want dinner and rice from one appliance. You want a simple 4-setting machine.
Watch outYou want texture settings for white rice.
How we researched this We compiled the specs from official maker pages and Japanese-language manuals and spec sheets (checked 2026-10-25). We have not bought or tested every product ourselves. Makers update their listings, so please confirm on the official page before you buy.