Common aspect ratios
An aspect ratio is width compared with height. Sizes with the same ratio have the same shape at any scale, so 1280 × 720, 1920 × 1080 and 3840 × 2160 are all 16:9.
| Ratio | Decimal | Example sizes | Where you see it |
|---|---|---|---|
| 1:1 | 1.00:1 | 1080 × 10802048 × 2048 | Square prints (8×8, 12×12), Instax Square, iPhone square photos |
| 5:4 | 1.25:1 | 1280 × 10242560 × 2048 | 8×10 and 16×20 prints (as 4:5); a Fujifilm X-T5 setting |
| 4:3 | 1.33:1 | 1024 × 7681600 × 12004000 × 3000 | Micro Four Thirds sensors; one of three iPhone Camera ratios |
| 3:2 | 1.50:1 | 1440 × 9606000 × 40007008 × 4672 | Full-frame and APS-C cameras such as the Sony α7 IV and Fujifilm X-T5; 4×6 prints |
| 16:10 | 1.60:1 | 1920 × 12002560 × 1600 | — |
| 16:9 | 1.78:1 | 1280 × 7201920 × 10803840 × 2160 | HDTV and 4K and 8K UHD TV (ITU-R BT.709 and BT.2020) |
| 21:9 | 2.33:1 | 2560 × 10803440 × 14405120 × 2160 | Ultrawide monitors (the resolutions are only close to 21:9) |
| 32:9 | 3.56:1 | 3840 × 10805120 × 1440 | Super-ultrawide monitors: two 16:9 screens side by side |
| 9:16 | 1.78:1 | 1080 × 19202160 × 3840 | Vertical video: 16:9 turned on its side |
How to calculate an aspect ratio
Divide the width and height by their greatest common divisor. For 1920 × 1080 the largest number that divides both is 120, so the ratio is 16:9. If no common divisor gets you to small numbers, as with 3440 × 1440 (43:18), the decimal form is easier to compare: divide width by height to get 2.39:1.
To resize while keeping the same ratio:
- New height = new width × original height ÷ original width. Scaling 1920 × 1080 to 1280 wide: 1280 × 1080 ÷ 1920 = 720.
- New width = new height × original width ÷ original height. A 3:2 photo 1,200 pixels tall is 1,200 × 3 ÷ 2 = 1,800 wide.
16:9 resolutions
16:9 is the picture shape set by ITU-R BT.709 for HDTV and BT.2020 for 4K and 8K UHD television, all with square pixels. Every width below gives a whole-number height:
| Width | Height | Megapixels | Common name |
|---|---|---|---|
| 640 | 360 | 0.2 | |
| 1280 | 720 | 0.9 | 720p |
| 1600 | 900 | 1.4 | |
| 1920 | 1080 | 2.1 | HDTV, ITU-R BT.709 |
| 2560 | 1440 | 3.7 | 1440p (QHD) |
| 3200 | 1800 | 5.8 | |
| 3840 | 2160 | 8.3 | 4K UHD, ITU-R BT.2020 |
| 5120 | 2880 | 14.7 | |
| 7680 | 4320 | 33.2 | 8K UHD, ITU-R BT.2020 |
4:3 and 3:2 resolutions
4:3 is the shape of Micro Four Thirds sensors (the OM-D E-M10 Mark IV's is 17.3 × 13 mm) and one of the iPhone Camera app's three ratios. 3:2 is where full-frame and APS-C cameras record their full resolution: the Sony α7 IV at 7,008 × 4,672 and the Fujifilm X-T5 at 7,728 × 5,152.
| 4:3 width | 4:3 height | 3:2 width | 3:2 height |
|---|---|---|---|
| 640 | 480 | 720 | 480 |
| 800 | 600 | 1080 | 720 |
| 1024 | 768 | 1440 | 960 |
| 1280 | 960 | 2160 | 1440 |
| 1600 | 1200 | 3000 | 2000 |
| 2048 | 1536 | 4500 | 3000 |
| 4000 | 3000 | 6000 | 4000 |
Aspect ratios of TVs, monitors, cameras and phones
Pixel counts as each maker or standard lists them, reduced to a ratio:
| Device | Pixels | Exact ratio | Sold as |
|---|---|---|---|
| HDTV (1080p) | 1,920 × 1,080 | 16:9 | 16:9 |
| 4K UHD TV | 3,840 × 2,160 | 16:9 | 16:9 |
| 8K UHD TV | 7,680 × 4,320 | 16:9 | 16:9 |
| Dell UltraSharp U3425WE (34" ultrawide) | 3,440 × 1,440 | 43:18 | 21:9 |
| Sony α7 IV (full frame) | 7,008 × 4,672 | 3:2 | 3:2 |
| Fujifilm X-T5 (APS-C) | 7,728 × 5,152 | 3:2 | 3:2 |
| iPhone 17 screen | 2,622 × 1,206 | 2.17:1 | — |
Apple doesn't give the iPhone 17 screen a ratio; 2,622 × 1,206 works out to 2.17:1, taller than 16:9 (1.78:1). That is within 0.3% of 19.5:9, the closest shape in the calculator's list. Cameras let you pick a ratio, which crops the sensor:
| Ratio setting | Fujifilm X-T5 | Sony α7 IV |
|---|---|---|
| 3:2 | 7,728 × 5,152 | 7,008 × 4,672 |
| 4:3 | 6,864 × 5,152 | 6,224 × 4,672 |
| 16:9 | 7,728 × 4,344 | 7,008 × 3,944 |
| 1:1 | 5,152 × 5,152 | — |
| 5:4 | 6,432 × 5,152 | — |
On both cameras 3:2 keeps the most pixels, because it uses the whole sensor. Choosing a camera? See our mirrorless camera picks.
Is a 21:9 monitor really 21:9?
Not exactly. Monitors sold as 21:9 use resolutions a little wider than 21:9. Dell lists its UltraSharp U3425WE as 21:9 at 3440 × 1440, which reduces to 43:18. True 21:9 is 2.33:1.
| Resolution | Exact ratio | Decimal |
|---|---|---|
| 2560 × 1080 | 64:27 | 2.37:1 |
| 3440 × 1440 | 43:18 | 2.39:1 |
| 5120 × 2160 | 64:27 | 2.37:1 |
The difference matters only when you make content to fit the screen exactly. More models are in our ultrawide monitor guide.
Aspect ratios of photo prints
Print sizes are named short side first, so the ratio reads upright: 4 × 6 is 2:3 (a 3:2 photo turned on its side), 5 × 7 is 5:7, 8 × 10 is 4:5, 11 × 14 is 11:14, and Instax Square's 62 × 62 mm picture is 1:1. The photo size chart groups every standard print by ratio and shows how much a camera or phone photo crops at each.
What happens when the ratios don't match?
Either part of the picture is cut off or bars fill the gap. A 4:3 photo shown full height on a 16:9 screen fills 75% of the width and leaves bars at the sides; zoomed to fill the width it loses 25% of its height. A 3:2 photo printed edge to edge on 8 × 10 loses 17% of its length. Crop it yourself first so you choose what goes, using this calculator to get the exact dimensions.
How this calculator works
It reduces width and height by their greatest common divisor (after scaling decimals to whole numbers) for the exact ratio, divides width by height for the decimal, and picks the nearest common ratio by comparing shapes. Resizing multiplies by the ratio and rounds pixel results to whole pixels. Device resolutions and ratio names come from the makers and standards listed below.
Sources
- ITU-R BT.709-6, Parameter values for the HDTV standards for production and international programme exchange www.itu.int/rec/R-REC-BT.709
- ITU-R BT.2020-2, Parameter values for ultra-high definition television systems www.itu.int/rec/R-REC-BT.2020
- Dell, UltraSharp 34 Curved Thunderbolt Hub Monitor U3425WE (tech specs) www.dell.com/en-us/shop/monitors/apd/dell-ultrasharp-34-curved-thunderbolt-hub-monitor-u3425we/u3425we_monitor/-
- Sony, α7 IV Help Guide: JPEG Image Size/HEIF Image Size helpguide.sony.net/ilc/2110/v1/en/contents/TP1000659393.html
- Fujifilm, X-T5 specifications (number of recorded pixels) www.fujifilm-x.com/en-us/products/cameras/x-t5/specifications/
- OM System, OM-D E-M10 Mark IV specifications explore.omsystem.com/us/en/om-d-e-m10-mark-iv
- Apple, iPhone User Guide: Use iPhone camera tools to set up your shot support.apple.com/guide/iphone/use-camera-tools-iph3dc593597/ios
- Apple, iPhone 17 Technical Specifications www.apple.com/iphone-17/specs/
- Fujifilm, INSTAX SQUARE SQ40 specifications (SQUARE film and picture size) www.fujifilm.com/us/en/consumer/instax/cameras/squaresq40/specifications
- Mpix, Photo Prints (print sizes) www.mpix.com/products/prints
Sources checked 2026-10-19.