The **ratio** of a flag is the proportion of its hoist (height) to its fly (length), expressed as two numbers separated by a colon, such as 2:3 or 1:2. Ratio is one of the most basic specifications of a flag and is often fixed by law. National ratios vary widely: the Swiss and Vatican flags are square (1:1), the United States is 10:19, and many Commonwealth countries follow the British 1:2.
**Example**: The flag of Nepal is unique among national flags in being non-rectangular; its specification gives the precise geometry rather than a simple ratio.
**See also**: [proportions](/glossary/proportions/), [ratio-codification](/glossary/ratio-codification/), [construction-sheet](/glossary/construction-sheet/), [hoist](/glossary/hoist/)