The size of a flag is determined by it's height and width and expressed as a ratio or decimal.
There are three main sizee of flags that account for the majority of flags.
1 / Commonwealth flags are traditionally twice as wide as they are high.
This is referred to as a 1:2 aspect ratio or given a decimal ratio of 2, which is the width divided by the height. There are 54 Sovereign States, (approximately 30%), using this size flag. (But curiously not the United States which uses 10:19 or 1:1.9)
2 / The most popular sized flag around the world is where the width is 1.5 times the height.
This is an aspect ratio of 2:3 or a decimal ratio of 1.5. There are 85 Sovereign States, (approximately 40%) around the world using this sized flag.
3 / The third size is where the width is 1 and 2/3 the height.
This flag has an aspect ratio of 3:5. The decimal ratio is 1.67. It is considered special because the aspect ratio is the closest to the Golden Ratio of 1.618. The Golden Ratio is often found in nature and is considered naturally very pleasing to the eye.
Many countries also use several differing configurations.
The Green and Gold Cross and Stars remains the same size, in all 3 variations in size.
It is the width of the Blue field or background that adjusts size to suit the width of the flag. There are actually a large number of widths between the smallest flag of one and a half times wide; to the twice as wide flag. The 1.67 is just one of those widths in between.
The design of the Southern Cross Flag allows for all three designs to be easily made and displayed in number of configurations without distortion and minimal adjustment.
The image at the top of the page shows the three flags as if all three were centred and placed on top of each other.
- The widest (with lightest blue outline) is 1:2
- The mid size (mid blue) is 3:5
- The shortest with dark blue shows the 2:3 wide flag
Why is it important to have a flag that adapts to all sizes?
Several hundred years ago a flag simply said to which county a ship or fort belonged. They were hand made and they were hoisted and flew.
Now this is not the case. The modern flag can be used for just about everything; from being worn, or used in marketing - almost anything you can think of. And only top quality flags are hand made.
It is not always possible to take a design and simply shrink it or increase it and have an accurate flag.
This becomes a major problem when lazy flag manufactures ignore the correct size of the flag and simply manufacture what is easiest for them - usually the default size of their own country.
Some wide flags are trimmed off one edge, which puts the flag out of proportion. An example of this would be the US flag. It could be "squared off" by cutting it in half. Or lengthened by just added to the stripes.
Other wider flags can be narrowed or short flags stretched. This usually distorts the features in the flag, this would happen with stars on the Australian Flag if it was reduced from twice the width (1:2) to one an a half times the width (2:3).
The Southern Cross Flag avoids that by simply trimming the edges of the Blue field. In that way the symbolism of the flag, where the Green and Gold Cross represent the land and beaches, and the Stars can easily remain in the proportions.
A case in point is this website. If you visit the Articles page you will see the articles with a "featured Image" The images are fixed size, and display as 1.5 times the height. There are at least 4 different width Southern Cross Flag shown, but even when cropped to 1.5X the height, the flag displays correctly. As does the Aboriginal Flag. Unfortunately many of the other flags do not.
The Size Variations
Note the 3 flags below. While the width varies the Cross does not. It does not get larger or smaller. The Cross remains the same size.
If it helps think of the Green and Gold Cross and Stars as the island continent of Australia (with the Stars above).
The Blue represents the ocean and seas that surround us.
On the shorter flags, there is just less sea. The wider flags show more ocean. But the Continent and Southern Cross always remain the same.
In the animation below, you can see that the Cross & Stars remain the same - they are not stretched or compressed as the size of the flag changes.
The 1:2 Aspect Ratio Flag
The Southern Cross flag is based on the traditional size of the flags of the British Empire. It is twice the width of the height. It has an aspect ratio of 1:2 or a decimal aspect ratio of 2.
A flag of this aspect ratio could be a flag waver of 15cm x 30cm or ones people take to sports around 1m x 2m, or or a larger one for a flagpole 3.2m x 6.4m
Did you notice how the Gold borders of the Cross encircle the Green Cross and show how this nation is also an island continent - the Green and Gold of Australia.
The 2:3 Aspect Ratio Flag
This is the world's most popular sized flag. It has an aspect ratio of 2:3 or a decimal ratio of 1.5. It is 50% wider than it is high.
A flag like this could be 20cm x 30cm, 1m x 1.5m x or 3.2m x 4.8m.
It is the same height as the one above, but more compact. With less weight, it is able to fly in gentle breezes. The Green & Gold Cross is the same size as the one above, but the blue field has been trimmed off either long edge, but retains enough blue to show Australia as a nation surrounded by water.
The 3:5 Aspect Ratio Flag
It has an aspect ratio of 3:5 decimal ratio of 1.667. It is 66.7% or 2/3 wider than it is high.
This is closest size to the Golden Ratio, (1.618) a proportion that is considered to be very pleasing to the eye. This is popular size for flag manufacturers.
A 3:5 configuration or 1.67, means the width is 1.67 x the height. A flag like this is often referred to as 3 feet x 5 feet or 90cm x 150cm (exactly 914 mm x 1,524mm)
The Green & Gold Cross is still the same size as the ones above, but the width fits between the 1:2 & 2:3 aspect flags.
Never considered in the past, modern designers forget the icons when designing their flags.
Icons are not usually meant to be flown but are often used on websites to indicate nationality.
The square and circle icons are used on this website.