Learn Japanese: Japanese Numbers 1–20

Mastering numbers is one of the most practical first steps in learning Japanese. Whether you are shopping in a Tokyo market, telling someone your age, or checking the time for a train, these twenty digits form the foundation of daily communication. This lesson covers the basic integers from One, or Ichi (いち), up to Twenty, known as Ni-jū (にじゅう). Understanding these building blocks will make it much easier to tackle more complex counting systems and grammar points as you progress.

One of the most helpful features of the Japanese numbering system is its logical and consistent structure. Once you have memorized the primary numbers from one to ten, you have already learned the components for the next set. To form numbers from eleven to nineteen, you simply combine the word for Ten, Jū (じゅう), with the single digit that follows it. For example, Eleven is Jū-ichi (じゅういち), and Fifteen is Jū-go (じゅうご).

This logic continues as you move into multiples of ten. To say Twenty, you place the number two before ten to create Ni-jū (にじゅう). This mathematical approach means you can build larger numbers by simply stacking these familiar sounds in a predictable order. Note that for numbers like Four, Yon (よん), and Seven, Nana (なな), these specific forms are used when creating numbers such as Fourteen, Jū-yon (じゅうよん), and Seventeen, Jū-nana (じゅうなな).