Convert Ja (자) to Centimeters (cm)

The exact ja-to-centimeter relationship

One ja (cheok), a traditional Korean length unit, equals 30.3cm, or 0.303m. To convert ja to centimeters, multiply the number of ja by 30.3. For example, 2 ja is 2×30.3=60.6cm, 5 ja is 151.5cm, and 10 ja is 303cm (3.03m). One ja divides into 10 chi, and one chi is 3.03cm. For scale, 5 ja is about 151.5cm, close to an adult's height. Long used for cloth and lumber, ja converts to cm with a single multiplication.

When Koreans search for ja

Ja appears most often when handling fabric for hanbok or bedding. When a draper cuts cloth by the ja, you check how many cm that is to gauge the length you need. When a hanok, traditional furniture, or door is dimensioned in ja, you convert to cm to match a modern tape measure. It also helps to understand elders who describe blanket or mattress sizes in ja. In woodworking or interior work, old drawings in ja are frequently converted to modern units.

Reference points and a caveat

The anchors are 1 ja=30.3cm=0.303m, 1 ja=10 chi, and 1 chi=3.03cm. Note that the ja varied slightly by era and use. The gokcheok used in Korea today is 30.3cm, but other historical measures like the pobaekcheok differed, so figures in old texts may not match. People also round ja to 30cm in casual speech, but it is exactly 30.3cm, so error grows over longer measurements. Based on the modern standard gokcheok, ja times 30.3 is exact.

Frequently asked questions

All unit & currency conversions →