So you've found the perfect dress, but cannot figure out the size? Will a five-kilogram bag of rice feed your family for a week? Those grapes look delicious, but how many grams is a bunch? If you come from a country that does not use the metric system, it is time to dig out your old math book and start practicing conversions.

Height and Weight

If you think you are of average height in the United States, you may be surprised at how tall you feel in some places in Japan. The Japanese use centimeters to measure height, so don't be surprised to hear the following:

Whether discussing your own weight, ordering a bag of rice, or buying fruit, familiarity with grams and kilograms will also come in handy.

Sizing for Women

If you are a woman interested in buying yofuku (Western-style clothing) while in Japan, it is important to know three body measurements in centimeters: basuto (“bust”), uesuto (“waist”), and hippu (“hips”). As far as dress sizes go, Japanese clothing stores use S for small, M for medium, and L for large. Pronunciations must be in katakana-style English so that “s” comes out like esu, “m” is emu and “l” is eru. Average bust, waist, and hip measurements for each size are as follows:

• Small: bust: 78cm; waist: 60cm; hips: 80cm

• Medium: bust: 82cm; waist: 63cm; hips: 90cm

• Large: bust: 85cm; waist: 66cm; hips: 92cm

When buying pants (zubon), waist, hips, and inseam measurements are taken into consideration.

• Small: inseam: 64 cm; waist: 58–64cm; hips: 82–90cm

• Medium: inseam: 67cm; waist: 64–70cm; hips: 87–95cm

• Large: inseam: 71cm; waist: 69–77cm; hips: 92–100cm

• Extra-large: inseam: 75cm; waist: 77–85cm; hips: 97–105cm

Socks (kutsushita or sokkusu) for women usually come in two sizes with ranges from 22 to 24 centimeters, and 24 to 26 centimeters. Shoes (kutsu or shuuzu) usually start at 22.5 and go up to 24.5 centimeters (about a women's size 7½).

Sizing for Men

Men's fashion follows a similar pattern with the focus being on waist and inseam measurements. Typical sizes are as follows:

• Small: inseam: 81cm; waist: 68–76cm

• Medium: inseam: 84cm; waist: 76–84cm

• Large: inseam: 87cm; waist: 84–94cm

• Extra-large: inseam: 90cm; waist: 94–104cm

Shoes and socks for men also come in limited sizes. They range from about 25.5 centimeters to 27.5 centimeters. A size 27 shoe is considered large. A size 28 may be described as “really big.”