## What is a 21:9 aspect ratio?

The 21:9 aspect ratio is an ultra-wide ratio generally used to represent ultrawide films and monitors, even though they aren't an exact match.

It became a marketing term because it has the same denominator as the standard HDTV 16:9 aspect ratio. The ratios that are also considered as "21:9" are 64:27 (2560x1080), 43:18 (13340x1440), and 12:5 (3840x1600)^{[1]}.

Example 1

LG advertised its 29-inch LG 29WN600 monitor^{[2]} and many other models as ultrawide monitors with an aspect ratio of 21:9, while it has a resolution of WFHD 2560 x 1080 with an exact ratio of 64:27.

Example 2

The Samsung 34" QLED Ultra WQHD curved monitor^{[3]} is advertised as a 21:9 aspect ratio, while it has a resolution of WQHD 3440 x 1440 with an exact ratio of 43:18.

The aspect ratio has a standard format of **21:9** or **W:H**, where **W** is the width and **H** is the height of an image, screen, or container. In digital space, the measurement unit is in pixels. You can pronounce it "**twenty-one by nine**" or "**twenty-one to nine**" aspect ratio.

## Common 21:9 resolutions

Here are the 21:9 resolutions you frequently see on cinema films and monitors.

Width (px) | Height (px) | Real Aspect Ratio | Standard |
---|---|---|---|

1680 | 720 | 21:9 | |

1920 | 800 | 12:5 | |

2520 | 1080 | 21:9 | |

2560 | 1080 | 64:27 | WFHD |

2880 | 1200 | 12:5 | |

3440 | 1440 | 43:18 | WQHD |

3840 | 1600 | 12:5 | |

4320 | 1800 | 12:5 | 4K 2K |

5120 | 2160 | 64:27 | 5K 2K |

5160 | 2160 | 43:18 | 5K 2K |

5760 | 2400 | 12:5 | |

6880 | 2880 | 43:18 | |

7680 | 3240 | 64:27 | |

7680 | 3200 | 12:5 | |

8640 | 3600 | 12:5 | 8K 3K |

10240 | 4320 | 43:18 |

## Common 21:9 screen sizes

Here are the width, height, and diagonal of various 21:9 image, video, or screen sizes in inches and centimeters.

Diagonal | Width | Height |
---|---|---|

1″ 2.54 cm | 0.92″ 2.33 cm | 0.39″ 1 cm |

2″ 5.08 cm | 1.84″ 4.67 cm | 0.79″ 2 cm |

3″ 7.62 cm | 2.76″ 7 cm | 1.18″ 3 cm |

4″ 10.16 cm | 3.68″ 9.34 cm | 1.58″ 4 cm |

5″ 12.7 cm | 4.6″ 11.67 cm | 1.97″ 5 cm |

6″ 15.24 cm | 5.51″ 14.01 cm | 2.36″ 6 cm |

7″ 17.78 cm | 6.43″ 16.34 cm | 2.76″ 7 cm |

8″ 20.32 cm | 7.35″ 18.68 cm | 3.15″ 8 cm |

9″ 22.86 cm | 8.27″ 21.01 cm | 3.55″ 9 cm |

10″ 25.4 cm | 9.19″ 23.35 cm | 3.94″ 10.01 cm |

11″ 27.94 cm | 10.11″ 25.68 cm | 4.33″ 11.01 cm |

12″ 30.48 cm | 11.03″ 28.02 cm | 4.73″ 12.01 cm |

13″ 33.02 cm | 11.95″ 30.35 cm | 5.12″ 13.01 cm |

14″ 35.56 cm | 12.87″ 32.68 cm | 5.51″ 14.01 cm |

15″ 38.1 cm | 13.79″ 35.02 cm | 5.91″ 15.01 cm |

16″ 40.64 cm | 14.71″ 37.35 cm | 6.3″ 16.01 cm |

17″ 43.18 cm | 15.63″ 39.69 cm | 6.7″ 17.01 cm |

18″ 45.72 cm | 16.54″ 42.02 cm | 7.09″ 18.01 cm |

19″ 48.26 cm | 17.46″ 44.36 cm | 7.48″ 19.01 cm |

20″ 50.8 cm | 18.38″ 46.69 cm | 7.88″ 20.01 cm |

21″ 53.34 cm | 19.3″ 49.03 cm | 8.27″ 21.01 cm |

22″ 55.88 cm | 20.22″ 51.36 cm | 8.67″ 22.01 cm |

23″ 58.42 cm | 21.14″ 53.7 cm | 9.06″ 23.01 cm |

24″ 60.96 cm | 22.06″ 56.03 cm | 9.45″ 24.01 cm |

25″ 63.5 cm | 22.98″ 58.37 cm | 9.85″ 25.01 cm |

26″ 66.04 cm | 23.9″ 60.7 cm | 10.24″ 26.01 cm |

27″ 68.58 cm | 24.82″ 63.03 cm | 10.64″ 27.01 cm |

28″ 71.12 cm | 25.74″ 65.37 cm | 11.03″ 28.02 cm |

29″ 73.66 cm | 26.66″ 67.7 cm | 11.42″ 29.02 cm |

30″ 76.2 cm | 27.57″ 70.04 cm | 11.82″ 30.02 cm |

32″ 81.28 cm | 29.41″ 74.71 cm | 12.61″ 32.02 cm |

34″ 86.36 cm | 31.25″ 79.38 cm | 13.39″ 34.02 cm |

40″ 101.6 cm | 36.77″ 93.39 cm | 15.76″ 40.02 cm |

42″ 106.68 cm | 38.6″ 98.05 cm | 16.54″ 42.02 cm |

43″ 109.22 cm | 39.52″ 100.39 cm | 16.94″ 43.02 cm |

48″ 121.92 cm | 44.12″ 112.06 cm | 18.91″ 48.03 cm |

50″ 127 cm | 45.96″ 116.73 cm | 19.7″ 50.03 cm |

55″ 139.7 cm | 50.55″ 128.4 cm | 21.67″ 55.03 cm |

58″ 147.32 cm | 53.31″ 135.41 cm | 22.85″ 58.03 cm |

60″ 152.4 cm | 55.15″ 140.08 cm | 23.64″ 60.03 cm |

65″ 165.1 cm | 59.74″ 151.75 cm | 25.6″ 65.04 cm |

70″ 177.8 cm | 64.34″ 163.42 cm | 27.57″ 70.04 cm |

75″ 190.5 cm | 68.94″ 175.1 cm | 29.54″ 75.04 cm |

77″ 195.58 cm | 70.77″ 179.77 cm | 30.33″ 77.04 cm |

83″ 210.82 cm | 76.29″ 193.77 cm | 32.7″ 83.05 cm |

85″ 215.9 cm | 78.13″ 198.44 cm | 33.48″ 85.05 cm |

86″ 218.44 cm | 79.05″ 200.78 cm | 33.88″ 86.05 cm |

97″ 246.38 cm | 89.16″ 226.46 cm | 38.21″ 97.05 cm |

98″ 248.92 cm | 90.08″ 228.79 cm | 38.6″ 98.05 cm |

## FAQs

How do I calculate the 21:9 aspect ratio?

The 21:9 aspect ratio is an ultrawide screen or image format that proportionally contains twenty-one units horizontally for every nine vertically. It can be calculated by dividing the width by height and getting a value of **2.33 (2.333334)**.

For example, the ratio between the width and height of the Ultrawide HD (1680 x 720), Ultrawide Full HD (2520 x 1080), and Ultrawide 4K UHD+ (5040 x 2160) resolutions are equal to **2.33**.