The only country with a non-rectangular flag, and the maths that fixes its shape

Nepal flies the only national flag on Earth that is not a rectangle. It is two stacked crimson pennants with a blue border, taller than it is wide, and its exact shape is not drawn to a ratio at all: the constitution sets it out as a geometric construction, and the proportion that falls out of it is an irrational number.

Why the flag is two pennants

Because it began as two separate flags. The double pennon combines individual pennants once used by rival branches of Nepal’s ruling dynasty, stacked into one rather than either branch giving up its symbol.

Pennant-shaped banners were the norm across the hill kingdoms long before the rectangle became the world’s default — a convention spread largely by European navies and colonial administrations. Nepal was never colonised, so nobody ever imposed the change, and the pennant shape simply stayed.

The shape is a construction, not a ratio

Nepal’s constitution does not give the flag’s proportions; it gives instructions for drawing it. Schedule 1 lays out a sequence of lines, arcs and measurements to be made with a compass and straightedge, and the shape appears as the result.

The geometry was fixed in 1962 by Shankar Nath Rimal, a civil engineer, at the request of King Mahendra. The inner red pennon has tidy proportions on its own; it is the uniform blue border running around two joined triangles that pushes the finished flag to about 1 : 1.21901 — a number with no exact fraction. An earlier version of our coverage gave the ratio as exactly 4:3. That describes part of the construction, not the finished flag, and we have corrected it.

What the sun, moon and colours mean

The moon stands for peace and the cool of the Himalaya; the sun for hard work and the heat of the southern lowlands. Crimson is the colour of bravery and of the rhododendron that blazes across the mid-hills each spring, and the blue border stands for peace.

Early versions of both emblems had human faces; the 1962 standardisation dropped them for the clean shapes flown today. Nepalis have long read the pairing as a wish that the nation last as long as the sun and moon.

The flag the Olympics had to make an exception for

At Tokyo 2020 the protocol manual named Nepal as the only exception to the standard flag size. Every other flag was sized by a fixed rectangle; Nepal’s was required instead to match the others’ height, so it could hang level beside them.

It is a neat illustration of why flag makers find it awkward: mass-produced versions approximate the curves by eye, and it is common to see the sun or moon drawn slightly off. The government’s technical drawing remains the only fully authoritative version.

How to spot it on a trek

The national flag is crimson with a sun and moon; the strings of coloured squares over every pass are something else entirely. Those blue, white, red, green and yellow cloths are Tibetan Buddhist prayer flags — devotional, not national — and first-timers mix the two up constantly.

The real flag flies over government posts, army and police checkpoints and lodges, from Kathmandu’s Durbar Squares to Everest Base Camp. You pass beneath it at the permit checkpoint that marks the start of almost every trekking route in the country.

Six more ways Nepal stands alone

The flag is only the first way Nepal breaks the mould. Eight of the ten highest mountains on Earth stand in Nepal or on its borders; only K2 and Nanga Parbat, in Pakistan, break the run — with a caveat about the count we set out in the fourteen-versus-eight explainer.

The Buddha was born at Lumbini, in Nepal’s southern Terai, not in India. Nepal was never colonised. It runs on the Bikram Sambat calendar, so it is the year 2083 there, and it keeps a 45-minute time zone, UTC+5:45. And it spans roughly 60 metres above sea level to 8,848.86 metres at the top of Everest — one of three ways to call a mountain the tallest — inside a country about the size of England.

Sources: Wikipedia, “Flag of Nepal” (ratio, 1962 standardisation, Tokyo 2020 protocol); Encyclopaedia Britannica, “Flag of Nepal”; Flags of the World.

Cover photo: CAPTAIN MEDUSA via Wikimedia Commons (CC BY-SA 4.0). Section photos: Atlantic Ambience via Pexels (Pexels licence); cottonbro studio via Pexels (Pexels licence); CP Khanal via Pexels (Pexels licence); Roman Saienko via Pexels (Pexels licence); Arjay Neyra via Pexels (Pexels licence).